A new report said that different types of pla...

A new report said that different types of plants can release some chemical into the air to help other plants. These chemical warnings all have the same purpose — to spread information about one plant's disease or infestation so other plants can defend themselves. But exactly how plants receive and act on many of these signals is still mysterious.

In this week’s Proceedings of the National Academy of Sciences, researchers in Japan offered some explanations. They had identified one chemical message and traced it all the way from release to action.

The scientists looked at tomato plants infested by a common pest, the cutworm. The researchers studied leaves from exposed and unexposed plants. They found one compound showed up more often in the exposed plants. The substance is called Hex Vic. When the scientists fed Hex Vic to cutworms, it knocked down their survival rate by 17%. The scientists identified the source of Hex Vic, and sprayed it lightly over healthy plants. Those plants were then able to start producing the cutworm-killing Hex Vic. Researchers confirmed that uninfected plants have to build their own weapons to fight off bugs and disease. How do they know when to play defense? They are warned first by their friendly plant neighbors.

It is a complex tale, and it may be happening in more plant species than tomatoes. It may also be happening with more chemical signals that are still unknown to us. Further studies are needed to increase agricultural efficiency.

1.Which is the way used by plants to warn their neighbors?

A. Using of winds.

B. Identifying the chemicals.

C. Releasing some chemicals.

D. Being exposed early.

2.It can be inferred from the text that ________.

A. farmers may benefit from the further studies

B. the phenomenon may be happening in less plant species than tomatoes

C. there are not chemical signals

D. plants are warned first by their neighbors

3.What’s the function of Hex Vic?

A. It sprays over healthy plants.

B. It shows up more.

C. It cures the disease.

D. It damages the cutworm’s body.

4.The passage is likely to appear in ________.

A. a newspaper advertisement

B. a physics textbook

C. a science magazine

D. a finance report

高二英语阅读理解中等难度题查看答案及解析

Junyan added that as a reporter she needed many different skills and ______ to learn new things.

A. was constantly challenged　　　 B. constantly challenged

C. was constantly challenging 　 D. had constantly challenged

高二英语单项填空中等难度题查看答案及解析

We have proof that you become what you eat. When you know the effects of different types of food, you can use your knowledge well and eat what you want to become.

Food has an impact on our physical and mental health. Have you ever heard any of the following advice?

Lettuce (莴苣) or milk can make you sleepy.

To stop feeling sleepy you should eat peanuts or dried fish.

Everyone has their own advice to give, which they have read about or have been told by older relatives. Some of these pieces of advice seem to contradict each other.

Eating chocolate makes you fat and gives you spots.

Chocolate contains the essential minerals: iron and magnesium (镁).

What we need to figure out is what type of chocolate to eat to get the benefits and how much of it to eat. We can do this by reading the list of ingredients (原料) on the chocolate bar package. Exactly how much real chocolate is in there? And how much of that do we need to eat to get the benefits of the minerals it contains?

Future restaurants might be named after the physical or mental state they hope to create. Their menus will list the benefits of each dish and drink. Some restaurants have already started this concept, and list the nutritional (营养的) content of their dishes on the menus.

Let’s take the restaurant “Winners” as an example. Their menu would list dishes specifically designed to help you win sports competitions. Or you could choose the Go-faster salad, which is a large bowl of mixed raw vegetables in a light salad dressing, giving you energy without making you gain weight. And what kind of dishes do you think would be on the menu at the “Clever Café”?

So what’s going to happen to hamburgers and biscuits? Will the concept of eating food, because it’s tasty, go out of fashion? Of course not! Junk food is also changing. If ice-cream is not good for children, can’t we give them fat-free, sugar-free tofu ice-cream? Unhealthy food is going out of fashion, so brands are changing. We are told not to drink cola because of the sugar and caffeine content so cola companies are making sugar-free and caffeine-free drinks. We are told dried fruit is a healthier snack than biscuits so some biscuit companies are making biscuits with added vitamins.

1.By saying “you become what you eat”, the writer means that ________.

A．you will become your own food

B．you will know what food is good by its appearance

C．food has an effect on your health

D．you will know the effects of different types of food

2.What does the underlined word “contradict” mean in the text?

A．Oppose to                             B．Help with

C．Have influence on                       D．Benefit from

3.How can we eat chocolate properly, according to the passage?

A．To eat chocolate containing the essential minerals.

B．To read the list of ingredients on the package.

C．To get advice from others before eating real chocolate.

D．To learn how much chocolate we can consume before eating.

4.Which is true about the future restaurants?

A．The food in “Winners” can ensure you to win sports competitions.

B．They might list the nutritional content of their dishes on the menus.

C．Hamburgers will disappear in these restaurants.

D．The Go-faster salad helps you go faster.

5.The concept of eating tasty food will not go out of fashion because ________.

A．the junk food companies are changing their brand names

B．biscuit companies are making dried fruit

C．junk food will become healthier than before

D．Cola companies are still making cola

高二英语阅读理解中等难度题查看答案及解析

We have known for a long time that flowers of different plants open and close at different times of day. This is so 1  that there seems to be no need to ask the reason for it. Yet no one 2  understands why flowers open and close like this at particular times. The process is not as 3  as we might think, as recent experiments have shown. In one study, flowers were kept in constant 4 . We might expect that the flowers, without any information about the time of day, did not open as they 5  do. As a matter of fact, they 6  to open at their usual time. This suggests that they have some mysterious(神秘的) way of knowing the 7 . Their sense of time does not 8  information from the outside world; it is, so to speak, inside them, a kind of “inner clock”.

This 9  may not seem to be very important. However, it was later found that not just plants but also 10 , including man, have this “inner clock” which 11  the working of their bodies and influences their activities. Men, then, are also influenced by this mysterious 12 . Whether we wish it or not, it affects such things in our life as our need for sleep, our need for food.

In the past, this did not really 13  because people lived in natural condition. In the 14  world, things are different; now there are spacemen, airplane pilots and, in ordinary life, a lot of people who have to work at night. It would be very 15 , then, to know more about the “inner clock”. Such things as flowers might help us understand more about ourselves.

1.A. familiar       B. strange      C. similar          D. special

2.A. partly     B. personally       C. really           D. willingly

3.A. complex        B. simple           C. mature           D. meaningful

4.A. quietness      B. darkness     C. loneliness       D. sadness

5.A. finally        B. completely       C. physically       D. normally

6. A. refused       B. decided      C. continued        D. failed

7.A. time           B. secret           C. process      D. study

8.A. deal with      B. add to           C. give away        D. depend on

9.A. discovery  B. activity     C. invention        D. method

10.A. beasts        B. animals      C. strangers        D. humans

11.A. controls      B. studies          C. measures     D. destroys

12. A. world        B. flower           C. power            D. experiment

13.A. happen        B. exist            C. matter           D. work

14.A. ancient       B. modern       C. wonderful        D. peaceful

15.A. hard      B. expensive        C. convenient       D. important

高二英语完型填空简单题查看答案及解析

阅读下面材料，在空白处填入适当的内容（1个单词）或括号内单词的正确形式。

Recently a new research has been reported. It said that many fathers of children experienced lots of injuries per year while playing with _1.______(they) children. Some fathers felt that it was the most dangerous thing of being a parent walking across the floor_2.____(cover) by toys. And some of them fell over because of clothes or other things that _3._____(throw) everywhere. Besides, a third of fathers were knocked down __4.____their young children when fighting with them and a quarter got hurt when playing football or climbing trees with them. In fact, young fathers one in five picked up an injury when doing something that wasn’t ___5.____(suit) for them.

The research also found that some of the fathers who were __6.___(serious) injured had to take time off work. __7.___, not all of them had medical insurances in place__8._____(prevent) the case that they were too ill to work. And they were more likely to face a situation____9.____ their mobile phones and holiday bookings declined sharply during illness. So the fathers took much __10.____(press) from both family and the work.

高二英语语法填空中等难度题查看答案及解析

For years I wanted a flower garden. I’d spend hours thinking of different things I could plant that would look nice together.

But then we had Matthew. And Marvin. And the twins, Alisa and Alan. And then Helen. Five children. I was too busy raising them to grow a garden.

Money was tight, as well as time. Often when my children were little, one of them would want something that cost too much, and I'd have to say, “Do you see a money tree outside? Money doesn't grow on trees, you know.”

Finally, all five got through high school and college and were off on their own. I started thinking again about having a garden.

I wasn't sure, though. I mean, gardens do cost money, and after all these years I was used to living on a pretty lean, no-frills budget.

Then, one spring morning, on Mother's Day, I was working in my kitchen. Suddenly, I realized that cars were tooting their horns as they drove by. I looked out the window and there was a new tree, planted right in my yard. I thought it must be a weeping willow, because I saw things blowing around on all its branches. Then I put my glasses on — and I couldn't believe what I saw. There was a money tree in my yard!

I went outside to look. It was true! There were dollar bills, one hundred of them, taped all over that tree. Think of all the garden flowers I could buy with one hundred dollars! There was also a note attached: “IOU eight hours of digging time. Love, Marvin.”

Marvin kept his promise, too. He dug up a nice ten-by-fifteen foot bed for me. And my other children bought me tools, ornaments, a trellis (棚架), a sunflower stepping stone and gardening books.

That was three years ago. My garden's now very pretty, just like I wanted. When I go out and weed or tend my flowers, I don't seem to miss my children as much as I once did. It feels like they're right there with me.

I live up in Michigan's Upper Peninsula, where winters are long and cold, and summers are too short. But every year now, when winter sets in, I look out my window and think of the flowers I'll see next spring in my little garden. I think about what my children did for me, and I get tears in my eyes — every time.

I'm still not sure that money grows on trees. But I know love does!

1．By saying “Do you see a money tree outside .….,” the mother actually means “_______”

A．Observation is the best teacher.                 B．Seeing is believing.

C．The outsider sees the most of the game.       D．It is not easy to gain money

2．The best title for the passage would probably be_______.

A．My flower garden          B．Marvin helps to realize my dream

C．Love in Michigan          D．Money grows on trees

3．The underlined word “no - frills” in the fifth paragraph is similar in meaning to_______.

A．wasteful         B．tight             C．absurd            D．helpful

4．From the last two paragraphs we can infer that the mother is_______

A．divorced when she was young

B．not caring for her kids any longer

C．alone but not at all lonely

D．prouder with her garden than with her kids.

高二英语阅读理解简单题查看答案及解析

It’s said that this kind of plant only gives off this strange perfume on ________ conditions which the scientists are trying to figure out now.

A. outstanding        B. certain            C. obvious         D. ordinary

高二英语单项填空简单题查看答案及解析

Now we can _________ weather information from a new type of weather satellites．

A．pick up   B．take up    C．keep up  D．set up

高二英语单项填空中等难度题查看答案及解析

Everybody hates it, but everybody does it. A recent report said that 40％of Americans hate tipping. In America alone, tipping is a $16 billion-a-year industry. Consumers acting politely ought not to pay more than they have to for a given service. Tips should not exist. So why do they? The common opinion in the past was that tips both rewarded the efforts of good service and reduced uncomfortable feelings of inequality. And also, tipping makes for closer relations. It went without saying that the better the service, the bigger the tip.

But according to a new research from Cornell University, tips no longer serve any useful function. The paper analyzes numbers they got from 2,547 groups dining at 20 different restaurants. The connection between larger tips and better service was very weak. Only a tiny part of the size of the tip had anything to do with the quality of service.

Tipping is better explained, by culture than by the money people spend. In America, the custom came into being a long time ago. It is regarded as part of the accepted cost of a service. In New York restaurants, failing to tip at least l5% could well mean dissatisfaction from the customers. Hairdressers can expect to get l5%-20%, and the man who delivers your fast food $2. In Europe, tipping is less common. In many restaurants the amount of tip is decided by a standard service charge. In many Asian countries, tipping has never really caught on at all. Only a few have really taken to tipping.

According to Michael Lynn, the Cornell papers’ author, countries in which people are more social or outgoing tend to tip more. Tipping may reduce anxiety about being served by strangers. And Mr. Lynn says, “In America, where people are expressive and eager to mix up with others, tipping is about social approval. If you tip badly, people think less of you. Tipping well is a chance to show off.”

1. This passage is mainly about ________.

2.Which of the following best explains the underlined phrase “caught on” ?

3. Among the following situations, in your opinion, who is likely to tip most?

4. We can infer from this passage that ________.

高二英语阅读理解困难题查看答案及解析

Companion planting is the idea that some kinds of plants can help each other grow. Plants that are compatible（兼容的，能共处的） together generally have similar needs in terms of nutrients，soil and moisture levels.

Advice about which plants are compatible is sometimes based more on tradition than proof. But experts say there is evidence to support certain combinations. These can improve harvests，reduce disease and help with pest control by attracting helpful insects.

For example，some kinds of soil bacteria take nitrogen from the air and make it into a form that plants can use. The plants hold the nitrogen in their roots. Legumes(豆科植物)are especially good at this nitrogen(氮)fixing. Then any crops that share the same space with the legumes can get the nitrogen when the roots are broken down.

Beans and potatoes can also share territory well because their roots reach different levels in the soil. Deep-rooted vegetables get nutrients and moisture from lower down in the soil，so they do not complete with plants with shallower roots.

But some plants placed together may harm each other's development. For example，tomatoes do not like wet soil but watercress does，so you would probably want to keep them separated.

Some kinds of produce should be kept apart even after being harvested. This is because of ethylene gas(乙烯气体)．Ethylene is a plant hormone(激素)that can cause some foods to ripen too quickly. Apples release ethylene gas. Apricots，melons and tomatoes also release a lot of ethylene. Some vegetables are easily affected by ethylene，including asparagus，broccoli，cabbage and cucumbers.

This risk of ripening too soon is why markets often separate high ethylene-producing foods from those that are sensitive to the gas. But if you put an apple in a bag with a green banana，the ethylene from the apple will make the banana ready to eat sooner.

What about peaches，plums and nectarines? These kinds of fruit do not need any help from an apple—they release enough ethylene to ripen themselves. But that does not mean there is no way to get the job done faster.

Growers suggest placing the fruit in a fruit bowl or in a paper bag with the top folded over. Keep the fruit at room temperature，out of direct sunlight. Once the fruit is soft enough，either use it or put it in the refrigerator to keep it from getting too ripe.

1.Companion planting refers to the idea that 　　　　　 ．

A. some crops can grow together to benefit each other

B. some crops have the similar needs of nutrients，soil and water level

C. some plants can damage each other if grown together

D. a good farming method to prevent natural disasters

2.According to the text，　　　　　 cannot grow together.

A. beans and potatoes B. tomatoes and watercress

C. legumes and corns D. rice and sugarcane

3.What is the function of ethylene?

A. To improve the quality of fruits. B. To produce a poisonous gas.

C. To keep vegetables fresh. D. To make fruits ripe earlier.

4.The text is most likely to be taken from　　　　　 ．

A. a newspaper of medicine B. a magazine of biology

C. a journal of agriculture D. a travel report

高二英语阅读理解中等难度题查看答案及解析