In 2011, during his freshman year at the University of Maryland, Simon was struck by how much food was thrown away in the college cafeteria. " I was shocked to see someone buy a full sandwich, eat half of it, and throw the other half out," said Simon. "It was not the values I grew up with. " To him, discarded food was a "natural goldmine” he could source to do good.
Four years later, Simon cofounded Imperfect Produce, a subscription-based home-delivery service for discounted “ugly" fruits and vegetables that are perfectly good on the inside, but otherwise rejected from the food supply chain for their looks.
“Up to 20% of the fruits and vegetables grown on farms in America are thrown away because the produce doesn't meet grocery stores" standards," said Simon. "It's often for discoloration, scarring on the surface caused by the fruit rubbing against a tree limb or an atypical shape,” he said. "Sometimes it's the size. " Simon, 29, and Chesler, 27, decided to source this "ugly" produce directly from farms and deliver it to customers for about 30% less than conventional grocery store prices.
"The reason why we created Imperfect Produce as a direct-to-consumer business is because grocery stores didn't want to partner with us,” said Simon. “So we became our own store. " The San Francisco-based service launched in August 2015. Today, Imperfect Produce has more than 200,000 subscribers in 22 cities. The company sources its produce from 250 growers nationwide, and slightly more than half of it is organic. To date, Simon said the service has helped recover 40 million pounds of food from going to waste.
Simon declined to disclose income but said this year's sales are expected to double last year's. The business is not yet profitable, but he hopes to expand the service to 40 cities by the end of 2019 and eventually take the company public at some point.
1.What does the underlined word “discarded” in Paragraph 1 refer to?
A.Wasted. B.Rejected.
C.Disliked. D.Eaten.
2.Why are many fruits and vegetables wasted?
A.They are not tasty. B.They are not nutritious.
C.They are poorly looking. D.They are not good inside.
3.What made Simon create Imperfect Produce as a direct-to-consumer business?
A.High price offered by him.
B.The wish to set up his own business.
C.His desire to offer service to others.
D.Grocery stores" unwillingness to cooperate with him.
4.What can be inferred about Simon?
A.He wants to help the poor.
B.He thinks a lot about the wasted food.
C.He has expanded his service to 40 cities.
D.He expects to make profits from his business.
高三英语阅读理解中等难度题
In 2011, during his freshman year at the University of Maryland, Simon was struck by how much food was thrown away in the college cafeteria. " I was shocked to see someone buy a full sandwich, eat half of it, and throw the other half out," said Simon. "It was not the values I grew up with. " To him, discarded food was a "natural goldmine” he could source to do good.
Four years later, Simon cofounded Imperfect Produce, a subscription-based home-delivery service for discounted “ugly" fruits and vegetables that are perfectly good on the inside, but otherwise rejected from the food supply chain for their looks.
“Up to 20% of the fruits and vegetables grown on farms in America are thrown away because the produce doesn't meet grocery stores" standards," said Simon. "It's often for discoloration, scarring on the surface caused by the fruit rubbing against a tree limb or an atypical shape,” he said. "Sometimes it's the size. " Simon, 29, and Chesler, 27, decided to source this "ugly" produce directly from farms and deliver it to customers for about 30% less than conventional grocery store prices.
"The reason why we created Imperfect Produce as a direct-to-consumer business is because grocery stores didn't want to partner with us,” said Simon. “So we became our own store. " The San Francisco-based service launched in August 2015. Today, Imperfect Produce has more than 200,000 subscribers in 22 cities. The company sources its produce from 250 growers nationwide, and slightly more than half of it is organic. To date, Simon said the service has helped recover 40 million pounds of food from going to waste.
Simon declined to disclose income but said this year's sales are expected to double last year's. The business is not yet profitable, but he hopes to expand the service to 40 cities by the end of 2019 and eventually take the company public at some point.
1.What does the underlined word “discarded” in Paragraph 1 refer to?
A.Wasted. B.Rejected.
C.Disliked. D.Eaten.
2.Why are many fruits and vegetables wasted?
A.They are not tasty. B.They are not nutritious.
C.They are poorly looking. D.They are not good inside.
3.What made Simon create Imperfect Produce as a direct-to-consumer business?
A.High price offered by him.
B.The wish to set up his own business.
C.His desire to offer service to others.
D.Grocery stores" unwillingness to cooperate with him.
4.What can be inferred about Simon?
A.He wants to help the poor.
B.He thinks a lot about the wasted food.
C.He has expanded his service to 40 cities.
D.He expects to make profits from his business.
高三英语阅读理解中等难度题查看答案及解析
Alison Malmon was completing the end of her freshman year at the University of Pennsylvania, US, when she got the news: Her older brother Brian, a student at Columbia University, was suffering from mental illness.
Influenced by this, Malmon formed a group at her university to enable students to talk openly about mental health. It soon blossomed into a national organization that today has more than 450 campus chapters. Leaders with the organization spend their time talking with college students about the pressure that today’s young people face. “What you hear often is just a need to be perfect,” said Malmon, “and a need to present oneself as perfect.”
And a new study in the UK proved that this need for perfectionism is simply part of today’s society. In the study, two researchers studied more than 40,000 students from the US, Canada, and the UK. They found that what they called “socially-prescribed (社会定向型的) perfectionism” increased by a third between 1989 and 2016.
Lead researcher Thomas Curran said that while so many of today’s young people try to present a perfect appearance online, social media isn’t the only reason behind this trend. Instead, he said, it may be driven by competition in modern society, meaning young people can’t avoid being sorted and ranked in both education and employment. That comes from new norms (准则) like greater numbers of college students, standardized testing and parenting that increasingly emphasizes success in education.
For example, in 1976, half of high school seniors expected to get a college degree of some kind. By 2008, more than 80 percent expected the same. The researchers also said changes in parenting styles over the last two decades might have had an impact. As parents feel increased pressure to raise successful children, they in turn pass their “achievement anxieties” onto their kids through “excessive (过多的) involvement in their child’s routines, activities or emotions.”
Those in the mental health community like Malmon say they’re concerned about the impact the culture of perfectionism has on mental health on campuses. “Mental health has truly become this generation’s social justice issue,” she said. “It’s our job to equip them with the tools and to let people know that it’s not their fault.”
1.What is the article mainly about?
A. The effects of the culture of perfectionism.
B. Research into the trend of perfectionism.
C. A group dedicated to helping people stay mentally healthy.
D. Various pressures that today’s young people are facing.
2.What inspired Alison Malmon to start a group related to mental health?
A. Her brother’s mental illness.
B. Her project during the freshman year.
C. The pressure she had experienced.
D. Her strong interest in mental health.
3.What may be pushing today’s young people to struggle to be perfect, according to the article?
a. The impact of social media.
b. Parents’ high expectations of their children.
c. The decreasing number of college students.
d. The fierce competition in society.
e. Their desire to draw their parents’ attention.
A. a, b, c B. a, d, e
C. a, b, d D. b, c, e
4.What does Malmon think is a way to help young people manage the pressure of perfectionism?
A. Enabling them to know what is to blame for their pressure.
B. Lowering their expectations of themselves.
C. Reducing parents’ involvement in their children’s life.
D. Making them aware of what true social justice is.
高三英语阅读理解困难题查看答案及解析
After their 20-year-old son hanged himself during his winter break from the University of Arizona five years ago, Donna and Phil Satow wondered what signs they have overlooked, and started asking other students for answers．
What grew from this soul searching was Ulifeline （www．Ulifeline．org）, a Web site where students can get answers to questions about depression by logging on through their universities．The site has been adopted as a resource by over 120 colleges, which can customize it with local information, and over 1．3 million students have logged on with their college ID’s．
“It is a very solid Web site that raises awareness of suicide, de-stigmatizes mental illness and encourages people to seek the help they need,”said Paul Grayson, the director of counseling services at New York University, which started using the service nearly a year ago．
The main component of the Web site is the Self-screening program developed by Duke University Medical Center that tests students to determine whether they are at risk for depression, suicide and disorders like anorexia and drug dependences．Besides helping students, the services compiles anonymous student date, offering administrators an important window onto the mental health of its campus．
The site provides university users with links to local mental health services, a catalog of information on prescription drugs and side effects, and access to Go Ask Alice, a vast archive developed by Columbia University with hundreds of responses to anonymously posted inquires from college students worldwide．For students concerned about their friends, there is a section that describes warning signs for suicidal behavior and depression．
Yet it is hard to determine how effective the service is．The anonymity of the online service can even play out as a negative．“There is no substitute for personal interaction（个人互动才能解决），” said Dr．Lanny Berman, executive director of the American Association of Suicidology, based in Washington．
Ulifeline would be the first to say that its service is no replacement for an actual therapist．“The purpose is to find out if there are signs of depression and then direct people to the right places,” said Ron Gibori, executive director of Ulifeline．
Mrs．Satow, who is still involved with Ulifeline, called it “a knowledge base” that might have prevented the death of her son, Jed．“If Jed’s friends had known the signs of depression, they might have seen something,” she said．
1.The first paragraph is written to_________．
A．report a suicide of a young man
B．show the suffering of Mr．And Mrs．Satow
C．describe the Satows’ confusion over their son’s death
D．introduce the topic of a website called Ulifeline．
2.One reason that many colleges adopt the website is to _________
A．provide their students with campus information
B．offer medical treatment to students in mental disorder
C．encourage their students to seek advice about depression
D．give their students various help they may need
3.Go Ask Alice as mentioned in the passage is________
A．a side effect caused by some prescription drugs
B．intended to counsel college students in mental problems
C．a collection of medical responses from students the world over
D．meant to describe the various signs of mental disorders
4.The underlined sentence of the seventh paragraph implies that ______
A．only actual therapy can ensure adequate treatment
B．the help given by the web service is doubtful
C．doctors have expressed a negative view of the service
D．a therapist’s office is the first place for the depressed to go
5.Mrs．Satow would probably agree that _________
A．Jed’s friends can prevent her son’s death
B．her son’s suicide is unavoidable
C．Ulifeline is a worthwhile website
D．depression is the final cause of suicides
高三英语阅读理解中等难度题查看答案及解析
After their 20-year-old son hanged himself during his winter break from the University of Arizona five years ago, Donna and Phil Satow wondered what signs they have overlooked, and started asking other students for answers.
What grew from this soul searching was Ulifeline (www. Ulifeline. org), a Web site where students can get answers to questions about depression by logging on through their universities. The site has been adopted as a resource by over 120 colleges, which can customize it with local information, and over 1.3 million students have logged on with their college ID’s.
“It is a very solid Web site that raises awareness of suicide, de-stigmatizes mental illness and encourages people to seek the help they need,”said Paul Grayson, the director of counseling services at New York University, which started using the service nearly a year ago.
The main component of the Web site is the Self-screening program developed by Duke University Medical Center that tests students to determine whether they are at risk for depression, suicide and disorders like anorexia and drug dependences. Besides helping students, the services compiles anonymous student date, offering administrators an important window onto the mental health of its campus.
The site provides university users with links to local mental health services, a catalog of information on prescription drugs and side effects, and access to Go Ask Alice, a vast archive developed by Columbia University with hundreds of responses to anonymously posted inquires from college students worldwide. For students concerned about their friends, there is a section that describes warning signs for suicidal behavior and depression.
Yet it is hard to determine how effective the service is. The anonymity of the online service can even play out as a negative. “There is no substitute for personal interaction(个人互动才能解决)，” said Dr. Lanny Berman, executive director of the American Association of Suicidology, based in Washington.
Ulifeline would be the first to say that its service is no replacement for an actual therapist. “The purpose is to find out if there are signs of depression and then direct people to the right places,” said Ron Gibori, executive director of Ulifeline.
Mrs. Satow, who is still involved with Ulifeline, called it “a knowledge base” that might have prevented the death of her son, Jed. “If Jed’s friends had known the signs of depression, they might have seen something,” she said.
1. The first paragraph is written to_________.
| A．report a suicide of a young man |
| B．show the suffering of Mr. And Mrs. Satow |
| C．describe the Satows’ confusion over their son’s death |
| D．introduce the topic of a website called Ulifeline. |
2.One reason that many colleges adopt the website is to _________
| A．provide their students with campus information |
| B．offer medical treatment to students in mental disorder |
| C．encourage their students to seek advice about depression |
| D．give their students various help they may need |
3. Go Ask Alice as mentioned in the passage is________
| A．a side effect caused by some prescription drugs |
| B．intended to counsel college students in mental problems |
| C．a collection of medical responses from students the world over |
| D．meant to describe the various signs of mental disorders |
4.The underlined sentence of the seventh paragraph implies that ______
| A．only actual therapy can ensure adequate treatment |
| B．the help given by the web service is doubtful |
| C．doctors have expressed a negative view of the service |
| D．a therapist’s office is the first place for the depressed to go |
5. Mrs. Satow would probably agree that _________
| A．Jed’s friends can prevent her son’s death |
| B．her son’s suicide is unavoidable |
| C．Ulifeline is a worthwhile website |
| D．depression is the final cause of suicides |
高三英语阅读理解中等难度题查看答案及解析
Lauren Berger started out as a clueless college freshman at the University of Central Florida，________ only work experience was serving at a seafood restaurant.
A．which B．when
C．whose D．where
高三英语单项填空中等难度题查看答案及解析
When next year’s crop of high-school graduates arrive at Oxford University in the fall of 2009, they’ll be joined by a new face; Andrew Hamilton, the 55-year-old provost (教务长) of Yale, who’ll become Oxford’s vice-chancellor—a position equivalent to university president in America.
Hamilton isn’t the only educator crossing the Atlantic. Schools in France, Egypt, Singapore, etc, have also recently made top-level hires from abroad. Higher education has become a big and competitive business nowadays, and like so many businesses, it’s gone global. Yet the talent flow isn’t universal. High-level personnel tend to head in only one direction: outward from America.
The chief reason is that American schools don’t tend to seriously consider looking abroad. For example, when the board of the University of Colorado searched for a new president, it wanted a leader familiar with the state government, a major source of the university’s budget. “We didn’t do any global consideration,” says Patricia Hayes, the board’s chair. The board ultimately picked Bruce Benson, a 69-year-old Colorado businessman and political activist (活动家) who is likely to do well in the main task of modern university presidents: fund-raising. Fund-raising is a distinctively American thing, since U.S. schools rely heavily on donations. The fund-raising ability is largely a product of experience and necessity.
Many European universities, meanwhile, are still mostly dependent on government funding. But government support has failed to keep pace with rising student number. The decline in government support has made funding-raising an increasing necessary ability among administrators and has hiring committees hungry for Americans.
In the past few years, prominent schools around the world have joined the trend. In 2003, when Cambridge University appointed Alison Richard, another former Yale provost, as its vice-chancellor, the university publicly stressed that in her previous job she had overseen “a major strengthening of Yale’s financial position.”
Of course, fund-raising isn’t the only skill outsiders offer. The globalization of education means more universities will be seeking heads with international experience of some kind of promote international programs and attract a global student body. Foreigners can offer a fresh perspective on established practices.
1.What is the current trend in higher education discussed in the passage?
A.Institutions worldwide are hiring administrators from the U.S.
B.A lot of political activists are being recruited as administrators.
C.American universities are enrolling more international students.
D.University presidents are paying more attention to funding-raising.
2.What is the chief consideration of American universities when hiring top-level administrators?
A.The political correctness.
B.Their ability to raise funds.
C.Their fame in academic circles.
D.Their administrative experience.
3.What do we learn about European universities from the passage?
A.The tuitions they charge have been rising considerably.
B.Their operation is under strict government supervision.
C.They are strengthening their position by globalization.
D.Most of their revenues come from the government.
4.Cambridge University appointed Alison Richard as its vice-chancellor chiefly because _____.
A.she was known to be good at raising money
B.she could help strengthen its ties with Yale
C.she knew how to attract students overseas
D.she had boosted Yale’s academic status
5.In what way do top-level administrators from abroad contribute to university development?
A.They can enhance the university’s image.
B.They will bring with them more international faculty.
C.They will view a lot of things from a new perspective.
D.They can set up new academic disciplines.
高三英语阅读理解简单题查看答案及解析
When next year’s crop of high-school graduates arrive at Oxford University in the fall, they will be joined by a new face: Andrew Hamilton, the 55-year-old provost (教务长) of Yale, who will become Oxford’s vice-chancellor –– a position equal to university president in America.
Hamilton isn’t the only educator crossing the Atlantic. Schools in France, Egypt, Singapore, etc. have also recently made top-level hires from abroad. Yet the talent flow isn’t universal. High-level personnel (人员) tend to head in only one direction: Outward from America.
The chief reason is that American schools don’t tend to seriously consider looking abroad. For example, when the board of the University of Colorado searched for a new president, it wanted a leader familiar with the state government, a major source of the university’s budget. “We didn’t do any global consideration,” says Patricia Hayes, the board’s chair. The board finally picked Bruce Benson, a 69-year-old Colorado businessman and political activist who is likely to do well in the main task of modern university presidents: fund-raising. Fund-raising is a particularly American thing, since U.S. schools rely heavily on donations. The fund-raising ability is largely a product of experience and necessity.
Many European universities, meanwhile, are still mostly dependent on government funding. But government support has failed to keep pace with rising student numbers. The decline in government support has made fund-raising an increasingly necessary ability among administrators (管理人员), and has made hiring committees hungry for Americans.
In the past few years, well-known schools around the world have joined the trend. In 2011, when Cambridge University appointed Alison Richard, another former Yale provost, as its vice-chancellor, the university publicly stressed that in her previous job she had overseen (监督) “ a major strengthening of Yale’s financial position”.
Of course, fund-raising isn’t the only skill outsiders offer. The globalization of education means more universities will be seeking heads with international experience of some kind to promote international programs and attract a global student body. Foreigners can offer a fresh perspective (视角) on established practices.
1. What is the current trend in higher education discussed in the text?
A．Institutions worldwide are hiring administrators from the U.S.
B．More international students are being admitted to American universities.
C．University presidents are paying more attention to fund-raising.
D．A lot of activists are being hired as administrators.
2. What do we learn about European universities from the text?
A．The tuition they charge has been rising considerably.
B．They are strengthening their position by globalization.
C．Their operation is under strict government control.
D．Most of their money comes from the government.
3. In what way do top-level administrators from abroad contribute to university development?
A．They can improve the university’s image.
B．They will bring with them more international personnel.
C．They will view a lot of things from a new angle.
D．They can set up new academic subjects.
4. Which of the following would make the best title of the text?
A．High Education Globalization
B．Global Headhunting in Higher Education
C．Global Higher Education Cooperation
D．Universal Higher Education Development
高三英语阅读理解中等难度题查看答案及解析
When next year’s crop of high-school graduates arrive at Oxford University in the fall, they will be joined by a new face: Andrew Hamilton, the 55-year-old provost (教务长) of Yale, who will become Oxford’s vice-chancellor –– a position equal to university president in America.
Hamilton isn’t the only educator crossing the Atlantic. Schools in France, Egypt, Singapore, etc. have also recently made top-level hires from abroad. Yet the talent flow isn’t universal. High-level personnel (人员) tend to head in only one direction: Outward from America.
The chief reason is that American schools don’t tend to seriously consider looking abroad. For example, when the board of the University of Colorado searched for a new president, it wanted a leader familiar with the state government, a major source of the university’s budget. “We didn’t do any global consideration,” says Patricia Hayes, the board’s chair. The board finally picked Bruce Benson, a 69-year-old Colorado businessman and political activist who is likely to do well in the main task of modern university presidents: fund-raising. Fund-raising is a particularly American thing, since U.S. schools rely heavily on donations. The fund-raising ability is largely a product of experience and necessity.
Many European universities, meanwhile, are still mostly dependent on government funding. But government support has failed to keep pace with rising student numbers. The decline in government support has made fund-raising an increasingly necessary ability among administrators (管理人员), and has made hiring committees hungry for Americans.
In the past few years, well-known schools around the world have joined the trend. In 2011, when Cambridge University appointed Alison Richard, another former Yale provost, as its vice-chancellor, the university publicly stressed that in her previous job she had overseen (监督) “ a major strengthening of Yale’s financial position” .
Of course, fund-raising isn’t the only skill outsiders offer. The globalization of education means more universities will be seeking heads with international experience of some kind to promote international programs and attract a global student body. Foreigners can offer a fresh perspective (视角) on established practices.
1.What is the current trend in higher education discussed in the text?
A．Institutions worldwide are hiring administrators from the U.S.
B．More international students are being admitted to American universities.
C．University presidents are paying more attention to fund-raising.
D．A lot of activists are being hired as administrators.
2.What do we learn about European universities from the text?
A．The tuition they charge has been rising considerably.
B．They are strengthening their position by globalization.
C．Their operation is under strict government control.
D．Most of their money comes from the government.
3.In what way do top-level administrators from abroad contribute to university development?
A．They can improve the university’s image.
B．They will bring with them more international personnel.
C．They will view a lot of things from a new angle.
D．They can set up new academic subjects.
4.Which of the following would make the best title of the text?
A．High Education Globalization
B．Global Headhunting in Higher Education
C．Global Higher Education Cooperation
D．Universal Higher Education Development
高三英语阅读理解中等难度题查看答案及解析
Jeremy Kerr, a researcher at the University of Ottawa in Canada, and his colleagues analyzed more than 400,000 observations of bumblebee species collected in North America and Europe from 1975 to 2010. When the researchers recorded the locations of these bee populations, they found that many of the 67 species analyzed were moving northward from their southern limits while the northern edges of the bees’ ranges are staying in place. What it results in is obvious.
Bees have been paid more attention to in recent years, with populations of honeybees and bumblebees obviously declining in some parts of Europe. Previously, attention on the decline of bee populations has focused on causes including habitat loss, pesticide use and the spread of bee parasites(寄生虫). But the work by Kerr’s team found something different.
"For every species, there is one or two species declining and others that are not moving at all," says Kerr. This shift has also been observed in other species, such as butterflies. But due to a new cause — the rise of temperatures instead of total pesticide use, a change in land use or parasites, bumblebees — unlike butterflies — have failed to extend the northern boundaries of their ranges into the territory that is now habitable for them, so bumblebee species across Europe and North America are declining rapidly, the latest study led by Kerr’s team finds. "Our data suggest that the new factor plays a leading, or perhaps the leading, role in this trend," says Kerr.
"This study shows that a fourth factor is also beginning to affect it. It is likely that the combined stresses from all of these pressures will have destructive impacts on bumblebees in the not-too-distant future," says Dave Goulson, a bee researcher at the University of Sussex, Brighton, UK.
Exactly what can be done to help bumblebees is not clear. Kerr’s team suggests that relocating colonies might be an answer but Goulson says that because the insects are mobile they are capable of moving northwards if there is suitable habitat available.
1.What does the move of the bees’ southern limits lead to?
A. The birth of new bee species.
B. The rise of the bees’ population.
C. The evolution of the bees.
D. The reduction of the bees’ habitat.
2.What’s the new cause of bee populations’ declining according to Kerr?
A. Habitat loss.
B. Pesticide use.
C. Climate change.
D. The spread of bee parasites.
3.Which statement may Goulson agree with?
A. Relocating bumblebees isn’t much good.
B. The findings of Kerr’s study are doubtful.
C. The future of bumblebees is still promising.
D. Knowing bumblebees’ living habits is the most urgent.
4.What kind of writing is this passage?
A. A book review.
B. An announcement.
C. A scientific report.
D. An official report.
高三英语阅读理解中等难度题查看答案及解析
When I began my freshman year of college at the age of fifty, I was scared and felt frustrated by the experience. It seemed as if I didn’t blend in(融入) with my classmates, and I found myself struggling academically. I searched to find some help in the college, but wasn’t able to find much.
My experience made me realize that there was a need for a group who could help the non-traditional students become successful and be better used to college life. I worked to help ESU (educational service unit) create such a group. We have to deal with study, family and our jobs at the same time. I wanted to provide resources to help make the change easier and less scary than my own experience was.
The group I set up has now grown to over seventy members who help old students and support one another. We’re currently working on a program to provide free babysitting for any college student that might need childcare. This would make things like studying in the library during the final weeks much easier.
Helping to found this student organization makes me feel wonderful inside. I would love to know that by forming this group, it has helped so many non-traditional students on their college journey. Success can be measured in many different ways. I measure my success by helping others and giving back when I can. My grandmother often told me the world would be a better place if we cared about and helped each other. People don’t care how much you know until they know how much you care—show them your care.
1.What’s the purpose of the first paragraph?
A. To complain about the difficulties in college.
B. To ask for help in academics.
C. To introduce the background of the topic.
D. To describe the author’s interesting experience.
2.It can be inferred from the passage that the author’s group ________.
A. aims to reduce old students’ pressure from life
B. mainly deals with academic problems
C. wants to help others get used to the jobs
D. mainly looks after children for old students
3.Through the group, the author ________.
A. feels successful
B. realizes her dream
C. understands her grandmother’s words
D. is happy to know she is cared about
高三英语阅读理解中等难度题查看答案及解析