It took 100 years, but finally, scientists, f...

It took 100 years, but finally, scientists, from CalTech, MIT and the LIGO Scientific Collaboration, proved Albert Einstein's theory that gravitational(引力的) waves exist. The waves were predicted as part of Einstein's General Theory of Relativity nearly 100 years ago. It was the theory of the physics behind the workings of our world and the universe. The idea was that the waves are like ripples in space, caused by some of the violent and energetic processes in the Universe. For example, two black holes crashing into each other.

What are these gravitational waves? Well, imagine throwing a rock into a pond. When the rock hits the flat surface of the water, it creates ripples or waves. Space time is like the surface of the water. So that means gravitational waves are like the ripples moving out from where the rock hits the water. It might be hard to understand, but those gravitational waves expand and contract space and time as they move through space. And when they get to the Earth, the waves pass through, and contract and expand the planet as the wave goes by.

It was Einstein who said these gravitational waves should be observable. But these are not huge waves. They are very, very small, which is why it took so long to find them. You cannot see them with your eyes. They are smaller than the size of an atom.

How did the scientists find them? For years, scientists have been watching two black holes in another galaxy faraway with the help of the Laser Interferometer Gravitational-Wave Observatory. The two were spinning around each other, moving closer and closer together. When they finally crashed into each other, it was with such power and force, that gravitational waves rang throughout the universe, like a giant bell. Those waves, traveling at the speed of light, finally reached the Earth, some 1.3 billion years later. They are the same waves that the scientists announced this past week.

The National Science Foundation tweeted that each of the black holes was thought to be 29 to 36 times the mass of our sun. So, what does this discovery mean? Abhay Ashtekar, a Penn State physicist, who was not on the discovery team, said: "Our understanding of the heavens changed dramatically."

1.According to the 1st paragraph, we can learn that_______.

A. gravitational waves were part of Einstein's General Theory of Relativity

B. scientists proved that gravitational waves existed 100 years ago

C. gravitational waves were the theory of the physics behind the universe

D. gravitational waves result from two black holes crashing into each other

2.From the passage we can know that the gravitational waves______.

A. are not supposed to be observed.

B. are very huge.

C. are easy to be found.

D. can’t be seen with our eyes.

3.Why did scientists spend years watching two black holes?

A. Because they wanted to see how the two black holes crashed into each other.

B. Because they wanted to find the gravitational waves.

C. Because they wanted to see the gravitational waves reach the Earth.

D. Because they wanted to know how black holes formed.

4.What can we infer from the passage?

A. The discovery has no relation to Albert Einstein's theory

B. Throwing a rock into a pond can generate gravitational waves

C. The discovery will considerably affect people’s understanding of universe

D. gravitational waves can’t contract and expand the Earth

高二英语阅读理解困难题查看答案及解析

—— Have they made the final decision?

—— Yes, but it’s ________ likely that they will change their mind again tomorrow.

A. rather than B. other than C. less than D. or rather

高二英语单项填空困难题查看答案及解析

It was not until this year _____ scientists managed to make a cat and a goldfish disappear from sight using an invisibility cloak(斗篷)

A .that                 B. when             C. while               D. As

高二英语单项填空中等难度题查看答案及解析

Cable TV began in 1948 in the USA, but it took 50 years ________ 66 percent of American households

had it.

高二英语单项填空简单题查看答案及解析

Cable TV began in 1948 in the USA, but it took 50 years________ 66 percent of American households had it.

A. before                    B. after                      C unless                     D. since

高二英语单项填空中等难度题查看答案及解析

Cable TV began in 1948 in the USA, but it took 50 years ________ 66 percent of American households had it.

A.before B.when

C.after D.until

高二英语单项填空简单题查看答案及解析

A baby seal robot from Japan has came to the U.S. It's been sold in Japan for several years, but now the company has created a Florida-based unit, Paro Robots U.S. Inc., to sell the creature to places like nursing homes and hospitals. The robot, named Paro, is marketed as a therapeutic（治疗的）device that can help comfort people who have problems that can lead to social isolation（隔离）.

Takanori Shibata, a Japanese engineer, invented Paro. He says the robot, which weighs about 6 pounds, is able to respond to touch, light, and sound.

Shibata says he tried making robotic cats and dogs, but that people didn't find those convincing. "They expected too much,"' he says, and would compare the robot to real animals they had known. Few people have ever seen a live baby seal, so they aren't likely to draw comparisons between the robot and the real thing. So they accept Paro as a cute little companion.

The Vinson Hall Retirement Community in McLean held a recent event to showcase the robot and Virginia Long slowly came into the activity room. When a nurse put the robot on her lap, it began to shake slightly, and Long talked to it gently. “Why are you shaking? Are you cold?" she asked. The robot made a high sound, and Long laughed. She said she used to have a cat, “but somebody stole him." "Petting a seal is unusual," she said, "but a lot of people have strange animals.

But some experts say a robot is no replacement for a real animal. "One of the things that we've learned is that it is the unexpected and natural behavior of the living creature that adds so much value to people's experience. Any kind of newness can get the attention of people who are lonely and bored, but that doesn't necessarily help them live a meaningful life. It doesn't solve the problem that is really causing their lack of enjoyment of life," says Bill Thomas, a professor at the University of Maryland, Baltimore County.

1.What is the role of Paro?

A.To look after baby seals. B.To give relief to Patients.

C.To replace home-raised pets. D.To Provide medical examinations.

2.How did people feel about robotic cats?

A.Disappointed. B.Astonished.

C.Concerned. D.Amused.

3.What was Long's reaction to Paro?

A.She refused to get close to it. B.She showed it much affection.

C.She regarded it as her new cat. D.She was frightened to talk to it.

4.What do Bill Thomas's words suggest about Paro?

A.It is of great value to people.

B.It is not of great use in solving real problems.

C.It fails to catch older people's interest.

D.It can take the place of a living creature.

高二英语阅读理解中等难度题查看答案及解析

Every year, the brightest young scientists from around the globe come together to participate in the world’s largest pre-college science competition, the Intel International Science and Engineering Fair (ISEF). They demonstrate their knowledge of science and engineering to improve the way we work and live.

One of 2019’s winners, Katie Lu, found a method for removing oil from water. This concept can also be applied to the removal of microplastics from our oceans as well.

Here is what Katie told reporters:

My experience at Intel ISEF was amazing! I remember on judging day, walking the exhibit hall and looking at the people gathered outside waiting to get in. My teacher turned to me and said, “That’s the future right there.” It was so amazing to spend time with all of these participants who are going to do amazing things in the future.

My scientific career has taught me not to fear failure and not to be afraid to ask for help. It’s really easy to be overwhelmed (挫败) and wonder if what you’re doing is going to work out, but even if it doesn’t, it’s OK! Always look on the positive side! A failure now doesn’t mean you’re a failure forever. Failure makes success feel earned when it comes. Also, asking for help is good when you’re struggling. You learn how to do things a lot faster and more efficiently.

I’m shocked that some people are still skeptical about climate change. It is real, it is dangerous and it is one of the most important issues of our generation. Reducing carbon emissions isn’t a “should”, it is a “must” to continue living on the planet. Additionally, people aren’t really worried about their personal impact on the earth in terms of littering, overusing plastic or wasting resources. If we don’t curb harmful human activity before it’s too late, it will be a problem that affects all humans, not just those that contribute.

1.What seems to concern Katie most?

A.Ocean exploration.

B.The overpopulation on the earth.

C.Environmental problems.

D.The shortage of natural energy.

2.What can we learn from what Katie’s teacher said?

A.No Intel ISEF, no future.

B.All the talents are at the Intel ISEF.

C.The participants will make the future amazing.

D.Katie should try to do better than the other participants.

3.What does Paragraph 5 mainly tell us？

A.The setbacks Katie experienced in her science.

B.The relationship between failure and success.

C.Seeking help is a shortcut to doing things well.

D.What Katie has gained from her scientific career.

4.What does the underlined word “curb” in the last paragraph most probably mean?

A.Punish. B.Control.

C.Deny. D.Measure.

高二英语阅读理解中等难度题查看答案及解析

Years ago, I lived in a building in a large city. The next building was only a few feet away from mine. There was a woman who lived there, whom I had never met, yet I could see her seated by her window each afternoon, sewing or reading.

After several months had gone by, I began to notice that her window was dirty. Everything was unclear through the dirty window. I would say to myself, “I wonder why that woman doesn’t wash her window. It really looks terrible.”

One bright morning I decided to clean my flat, including washing the window on the inside.Late in the afternoon when I finished the cleaning, I sat down by the window with a cup of coffee for a rest. What a surprise! Across the way, the woman sitting by her window was clearly visible. Her window was clean!

Then it dawned on me. I had been criticizing her dirty window, but all the time I was watching hers through my own dirty window.That was quite an important lesson for me. How often had I looked at and criticized others through the dirty window of my heart, through my own shortcomings?

Since then, whenever I wanted to judge someone, I asked myself first, “Am I looking at him through my own dirty window?” I try to clean the window of my own world so that I may see the world about me more clearly.

1.“It dawned on me” in paragraph 4 probably means “________”.

A. I knew it grew light　　 B. it cheered me up

C. I began to understand it　　 D. it began to get dark

2.It’s clear that ___________.

A. the writer had never met the woman before　　 B. the writer often washed the window

C. they both worked as cleaners　　 D. they lived in a small town

3.From the passage, we can learn___________.

A. one shouldn’t criticize others very often

B. one should often make his windows clean

C. one must judge himself before he judges others

D. one must look at others through his dirty windows

高二英语阅读理解中等难度题查看答案及解析

Years ago, I lived in a building in a large city. The next building was only a few feet away from mine. There was a woman living there, and I had never met her, yet I could see she sat by her window each afternoon, sewing or reading.

After several months had gone by, I began to notice that her window was dirty. Everything was unclear through the dirty window. I would say to myself. “I wonder why that woman doesn’t wash her window. It really looks terrible.”

One bright morning I decided to clean my flat, including washing the window on the inside.

Late in the afternoon when I finished the cleaning, I sat down by the window with a cup of coffee for a rest. What a surprise! Across the way, the woman sitting by her window was clearly visible (看见). Her window was clean!

Then it dawned on me. I had been criticizing (批评) her dirty window, but all the time I was watching hers through my own dirty window.

That was quite an important lesson for me. How often had I looked at and criticized others through the dirty window of my heart, through my own shortcomings?

Since then, whenever I wanted to judge (评判) someone, I asked myself first, “Am I looking at him through my own dirty window?” I try to clean the window of my own world so that I may see the world about me more clearly.

1.The writer couldn’t see everything clearly through the window because _______.

A. the woman’s window was dirty

B. the writer’s window was dirty

C. the woman lived nearby

D. the writer was near-sighted

2.“It dawned on me” probably means “_______”.

A. I began to understand it　　 B. it cheered me up

C. I knew it grew light　　　 D. it began to get dark

3.It’s clear that ________.

A. the writer had never met the woman before

B. the writer often washed the window

C. they both worked as cleaners

D. they lived in a small town

4.From the passage, we can learn _______.

A. one shouldn’t criticize others very often

B. one should often make his windows clean

C. one must judge himself before he judges others

D. one must look at others through his dirty windows[

高二英语阅读理解中等难度题查看答案及解析