It happens from time to time: you feel terrib...

It happens from time to time: you feel terrible when you take your first bite of a certain food, but after eating more, you find yourself enjoying it. This is what is called an acquired taste. But why do our tastes change?

The answer, according to a recent study presented at an American Chemical Society meeting in Boston, lies in proteins in our saliva (唾液).

Most of us tend to think saliva, almost entirely made up of water, is “only a mouth lubricant (润滑剂) helping us to swallow food,” the New York Times said. However, it also contains many proteins, which can help break food down, protect our teeth and help in tasting food.

To explain how these proteins affect taste, a team of scientists from Purdue University in the US invited 64 volunteers to drink a bitter-tasting chocolate milk three times a day for six weeks and rated their tastes at the same time.

According to the research, the participants found a strong bitterness on the first day, but the unpleasant flavor came to decrease as time went on and finally disappeared.

That is not all that was changing. A noticeable increase in the levels of proline-rich (富含脯氨酸的) proteins was found in the saliva samples of the test subjects in the research period. These proteins serve to reduce the bitterness we taste and improve our adaptation to this flavor.

“We think the body adapts to reduce the negative feeling of these bitter compounds,” said Cordelia Running, a food scientist at Purdue University. “Saliva changes flavor, which in turn changes eating choices.”

This change in taste not only makes the food tastier, but also helps people keep an appetite for healthy food whose flavor might otherwise keep them away.

One day, these proteins may even be extracted (提炼) and used as a separate food additive that could help people stick to healthy food whose flavor they continue to dislike, researchers told Science Alert. And according to Running, even it doesn’t happen, the idea that “maybe some little piece of your body is actually trying to help you” could really benefit some people. Let’s wait and see.

1.What does the underlined phrase “an acquired taste” in Paragraph 1 refer to?

A. The appetite for healthy food.

B. A mouth lubricant helping to swallow the food.

C. Something that tastes very delicious at first bite.

D. A preference that is only formed after great repetitions.

2.What contributes to the changes of our taste?

A. Our negative feelings of food.　　 B. Our adaptation to this flavor.

C. The proteins in our saliva.　　 D. The flavor of the food.

3.Which of the following statements is TRUE according to the text?

A. Saliva consists of many proteins besides water.

B. The unpleasant flavor will increase with time going on.

C. A separate food additive has been extracted from the proteins.

D. Proteins have nothing to do with the changes of our taste.

4.What can we infer from the last paragraph?

A. There will be bitter candy in the future.

B. You can change the flavor as you like in the future.

C. The researches will go on studying these proteins.

D. It won’t be long before we can make unhealthy food healthy.

高二英语阅读理解中等难度题查看答案及解析

We all know that water is tasteless. But it happens from time to time: you pick up the bottle of water you didn’t finish yesterday, and it tastes strange. Most often, you tend to drop the bottle in the trash bin, believing that the water has gone bad. But is it true?

According to Time, of course not, taste has little to do with quality of water.

According to Time, when water is exposed to the air for 12 hours, carbon dioxide interacts with the H2O in the water, and the pH value lowers slightly. As a result, the water has a different taste.

“But it’s most likely safe to drink,” Norwegian expert Truls Krogh told Science Nordic. “If the water is covered and of good quality to start with, in principle it can last a thousand years. That’s because when water is fresh, it contains little organic matter. As long as water is held in clean glasses or bottles, no pollutants will enter it to harm our health.”

People in countries like the US, the UK and Australia usually drink tap water. According to Time, if tap water is drunk within six months, the chlorine (氯气) in the water will be enough to kill any bacteria and keep it safe to drink.

However, there are also some exceptions. If you accidentally put your fingers into water or store water in unclean containers day after day, microorganism (微生物) will enter the water.

With the help of surrounding temperature, and sunlight streaming through windows, these microorganisms multiply quickly. Sooner or later, the water will be in the charge of the unfriendly bacteria. And if you drink the water too often, then you’re more likely to be ill.

And what about water in plastic bottles? Heat and plastic are a bad combination, US researcher Kellogg Schwab stresses. When plastic bottles are used at high temperatures, they produce a chemical called BPA. BPA is something that affects hormones (荷尔蒙) and research has tentatively linked it to “several health damage, including heart disease and cancer”, Time reported.

Schwab suggests replacing disposable (一次性的) plastic bottles with the refillable containers made of metal or glass to deal with BPA.

1.The purpose of the first paragraph is to ________________.

A. show an example B. draw a conclusion

C. analyze a phenomenon D. introduce a topic

2.Which of the following may Truls Krogh agree?

A. If the water tastes different, we shouldn’t drink it.

B. The water held in a clean container is likely safe to drink.

C. Although kept fresh, water may still have much organic matter.

D. Covered water can last for a thousand years.

3.What can we infer from the passage?

A. BPA does little harm to our health.

B. Tap water is always safe to drink.

C. Microorganisms are easy to produce in the heat.

D. Disposable plastic bottles have been banned already.

4.What can be the best title of the passage?

A. Why Water is Tasteless B. How to Get Clean Water

C. Does Water Really Go Bad? D. Learn to Protect Water

高二英语阅读理解困难题查看答案及解析

When you are far away from home for the first time and have a lot to adjust to，you can't do it alone. However independent you are，it is good to have a roommate during your first year.

Living with someone helps ease your loneliness. Sure it may seem appealing to be able to play your music and turn up your TV as loud as you want, but coming home to an empty room every day can be depressing. If you have a bad day, you may want to talk to someone.

Friends are great sources of venting (宣泄), but friends can't always be there. Even worse, they may be self­centered and show no interest in your problem. It's not that roommates aren't like this, but even just small talk can help you feel better.

Having a roommate teaches you how to get along with people and settle conflict. You two should set up rules immediately and discuss what to do when there is conflict. If you two don't like each other，you still study，relax，and sleep in the same room. You must find a way to get along.

Finally，having a roommate exposes (使接触) you to different ways of living. Your roommate may come from a different city，and have different living habits. He or she also has different interests and personalities. You don't have to end up liking the same things your roommate does，but_______________________. You will be surrounded by many different people in college and have the chance to try things you never have before. Why not start learning from your roommate？

Having a roommate gives you the skills and personal background you will need to utilize (利用) when you are out on your own. Make the most of living with a stranger and besides，there will be plenty of opportunities for you to have your own room later in your college years.

1.What is the main purpose of writting the text. (no more than 10 words)

2.Complete the following statement with proper words. (no more than 8 words).

Even if you can__________, you can still benefit from the freshmen sharing the same dormitory with you.

3.Please fill in the blank with proper words or phrases to complete the sentence.(Please answer within 5 words.)

4.Do you agree with opinion that “You can share everything with your roommate”? Please give your reason. (Please answer within 30 words.)

5.What does the word “it” (line 1, paragraph 2) probably refer to? (no more than 15 words)

高二英语其他题中等难度题查看答案及解析

When you are far away from home for the first time and have a lot to adjust to，you can't do it alone. However independent you are，it is good to have a roommate during your first year.

Living with someone helps ease your loneliness. Sure it may seem appealing to be able to play your music and turn up your TV as loud as you want, but coming home to an empty room every day can be depressing. If you have a bad day, you may want to talk to someone.

Friends are great sources of venting (宣泄), but friends can't always be there. Even worse, they may be self­centered and show no interest in your problem. It's not that roommates aren't like this, but even just small talk can help you feel better.

Having a roommate teaches you how to get along with people and settle conflict. You two should set up rules immediately and discuss what to do when there is conflict. If you two don't like each other，you still study，relax，and sleep in the same room. You must find a way to get along.

Finally，having a roommate exposes (使接触) you to different ways of living. Your roommate may come from a different city，and have different living habits. He or she also has different interests and personalities. You don't have to end up liking the same things your roommate does，but try to learn something different. You will be surrounded by many different people in college and have the chance to try things you never have before. Why not start learning from your roommate？

Having a roommate gives you the skills and personal background you will need to utilize (利用) when you are out on your own. Make the most of living with a stranger and besides，there will be plenty of opportunities for you to have your own room later in your college years.

1.Who are probably the intended readers of the passage？

A. University teachers.

B. Students who are not independent.

C. Students in the first year of college.

D. Students who will graduate from college soon.

2.From the passage，we can learn that 　　　.

A. roommates will become good friends in the end

B. there may be disagreements between roommates

C. students can choose those they like as their roommates

D. those with similar interests can become roommates

3. How is the passage organized？

4.The purpose of the passage is to　　　.

A. tell the importance of friends

B. compare friends with roommates

C. encourage students to find a roommate

D. state the different ways of living

高二英语阅读理解中等难度题查看答案及解析

—I haven’t heard from Henry for a long time.

—What do you suppose____ to him?

A. was happening  B. to happen       C. had happened        D. has happened

高二英语单项填空中等难度题查看答案及解析

It happens in plants when gardeners take cuttings from growing plants to make new ________ .

高二英语单项填空简单题查看答案及解析

At times when you are feeling low or you are let down, you seem to need some kinds of emotional or mental support. You usually speak to your closest friends or dearest family members during times of hardship to ease the burden.1.You are supposed to listen to it. Here are some tips to improve your inner voice.

2.Many people have trouble letting go of negative thoughts that they have about themselves. These negative thoughts often come from outside people whose opinion we value and from whom we seek love and being accepted.

If you find yourself feeling negatively about yourself and you are less perfect, take three simple steps. Stop your current line of thinking, and then pay attention to the effort that will be required to work towards a goal, then steadily apply the required effort.3.It can help you appreciate your own good work.

Saying “I am such a failure” after getting fired from a job is inaccurate and unfair to you. Instead, make the useful comment, “I lost my job, but I can use this experience to find and keep a new job.”4.You can think like this, “I don’t know how to do this basic home repair. Perhaps I could take a class and learn to do this in the future.”

Do not believe the worst can happen. It can be easy to feel that the most unpleasant result will take place with every situation.5.

A. You should overcome negative beliefs about yourself.

B. Focusing only on the negatives in your life is a bad habit.

C. During these times, your inner voice automatically gives its decision.

D. If you feel absurd, it’s more likely that you lack knowledge about something.

E. You had better change your focus from a final product to the struggle behind a task.

F. Your inner voice is always right most of the times because it knows better than others.

G. However, changing your inner thoughts to be realistic or truthful can help you avoid it.

高二英语七选五中等难度题查看答案及解析

If you want to cook something quickly, you heat it from both sides. That’s what’s happening to the West Antarctic ice sheet(南极洲西部冰盖). A new study reveals that the area under the ice sheet is far hotter than previously thought, fed by an unexpected flow of geothermal energy(地热能). While the CO2 we send out heats the atmosphere above the continent, earth is melting us ice from below.

If you were to drill (钻) deep at some place on the continents, you would find that the temperature increases about 25℃ for every kilometer deep into the hole on average. Scientists call this the geothermal gradient(地热梯度). Until recently, no one had drilled deeply enough through the West Antarctic ice to determine the geothermal gradient underground. For the new study, researchers drilled all the way through the ice and into the mud. They found that the geothermal gradient was about 200℃, which is several times the global average on continents. Few predicted this result, although it had been showed that the earth below the West Antarctic ice is unusually hot.

Even with the new discovery, though, we still don’t know exactly where the heat is coming from. One interesting possibility is volcanoes, which are under the ice. As recently as 2013, scientists were still discovering volcanoes under the ice in the area, and there may be many more.

Some people say that these volcanoes, rather than manmade climate change, are responsible for melting the area’s ice. While it’s true that heat coming from within the earth, including heat related to volcanoes, makes the melting faster, it is just one contributor to the loss of the West Antarctic ice sheet---not the main cause. Today’s study could help us understand how the whole system, including global warming, is melting the ice.

1.What’s happening to the West Antarctic ice sheet?

A. The ice sheet is getting hotter and hotter.

B. It is heated from below rather than from above.

C. The ice sheet is producing a new kind of energy.

D. It is melting from both sides.

2.What can be learned from the second Paragraph?

A. It was the first time that researchers had tried to measure geothermal gradients.

B. The geothermal gradient showed where the heat came from.

C. The result was beyond the researchers’ expectations.

D. Researchers never knew the earth under the West Antarctic ice was hot.

3.The author would probably agree that ___.

A. the new discovery is unhelpful without a certain conclusion

B. no volcano has been found to support the researchers’ idea

C. volcanoes are the most important reason for the melting of the ice

D. global warming is surely one reason for the melting of the ice

4.What’s the main idea of the passage?

A. The West Antarctic ice sheet is in danger.

B. Researchers are trying to stop global warming.

C. The West Antarctic ice sheet’s melting will bring terrible consequences.

D. It has been known how to stop the melting of the West Antarctic ice sheet.

高二英语阅读理解中等难度题查看答案及解析

--- I’m feeling terrible. I feel pain here and there.

--- Oh.　　　　 . Nothing seriously.

A. Go slowly　　　　　 B. Take it easy

C. Stay longer　　　 D. See you

高二英语单项填空中等难度题查看答案及解析

When a big exam is coming up, you probably feel anxious about any wasted time and want to begin school as soon as you probably can.

But tens of thousands of British high school students will soon be getting up later. They’re taking part in a new experiment by Oxford University to see if later classes can improve their exam results.

Grades 10 students in the UK have to take the nationwide General Certificate of Secondary Education (GCSE) exams. They have to pass these exams in order to study more advanced courses, and later apply for universities.

The Oxford University project means that GCSE students from more than 100 schools across England will start school at 10 am, more than one hour later than the current start time (8:50 am).

The project is based on scientific evidence that teenagers are “out of sync(同步)” with traditional school hours, the Telegraph reported. And what they need is more sleep in the morning.

“We know that something funny happens when you’re a teenager, in that you seem to be out of sync with the world,” said professor Colin Epsie, who is leading the study. “Your parents think it’s because you are lazy and opinionated（固执己见的）and everything will be OK if you could get to sleep earlier. But science is telling us that teenagers need to sleep more in the mornings.”

Everyone follows a natural cycle of sleep and wakefulne ss. Biology has decided that teenagers go to sleep around midnight and don’t feel fully awake until 9-10 am, according to scientists. That’s two hours later than adults. And their body clocks stay like this until the age of around 21 for males, and 19 for females.

“Society provides school for learning, but the brain provides sleep. So we are exploring the possibility that if you delay the schools start time until 10 am, that will improve learning performance,” said Epsie.

The results could be positive, based on previous studies.

An early study at the UK’s Monkseaton High School in 2009 found that starting an hour later improved grades in core subjects by 19 percent.

The Oxford project is expecting to publish the results in 2018. It’s time to wait and see whether scientists will give us an excuse to get up late.

1.According to the article, students who take part in the Oxford University project 　　　　　　　　　　　　　　　　　　 _________.

A. will start school one hour earlier

B. will no longer have to take GCSE exams

C. will perform better academically than those who don’t participate

D. will be guaranteed more sleeping time in the morning

2. The underlined phrase “out of sync”in Paragraph 5 probably means _____________ .

A. breaking the habit of doing something

B. getting used to doing something

C. having no idea of something

D. having trouble keeping up with something

3.We can infer from the article that _______________ .

A. the Oxford University project is targeted at all British high schools

B. getting up late is a sign of laziness in the eyes of most British parents

C. children and adults have different natural cycles of sleep and wakefulness

D. there is still no scientific evidence that supports a late school start time

4. What is the author’s attitude toward the Oxford University project ?

A. Critical　　　　 B. Optimistic

C. Doubtful　　　　 D. Uninterested

5. What’s the best title of the article ?

A. Wake up late to excel

B. It’s never too late to learn

C. The later you get up, the better you’ll learn

D. An excuse to get up late

高二英语阅读理解中等难度题查看答案及解析