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Sweet peas, cucumbers, grapes ---- what do you think they have in common?
None of these vegetables grow on trees. They all don’t have strong roots, big trunks or long branches, which makes it harder for them to get sunlight. But don’t worry. They have developed their own unique way of growing taller climbing!
Take sweet peas as an example. The plant grows as a straight stem until it finds something to hold onto, either a nearby tree or a stick. That is when the stem makes small coil(卷曲) that helps the plant hold the stick tightly.
How these plants are able to do this has been a mystery to scientists for years. Even Charles Darwin was interested in this question. But it is not until now that a Harvard research team has finally found the answer. The study was published in the Journal Science earlier this month.
The key, as it turns out, is inside a kind of thread-like cell called “g-fiber cell”, which has the ability to shrink or stretch. Each stem of the pea plant is made of several layers of g-fibers. Once the plant finds something to hold onto, cells on side of the stem start to shrink, forcing the whole thing to bend and coil, which is a bit like how our muscles get our bodies to move.
What’s more, a pea’s coil is not exactly like that of a spring. If you look closely, you may find that a spring coils all in the same direction, but a plant’s coil is in two opposite directions, like a telephone line. This means that the stem can stay soft when pulled gently but become strong enough when pulled harder.
“You want the plant to have a little bit of flexibility(柔韧性) so that if the wind blows or an animal disturb it, it doesn’t break,” explained Sharon Gerbode, author of the study. “This structure allows the plant to easily accommodate small movement, but then if something really serious happens it can become strong and protect itself.”
1. According to the article, coiling happens in sweet peas plant to allow the plant to .
A. form a straight stem
B. grow strong roots
C. develop g-fiber cells on the stems
D. climb itself up toward the sunlight
2.According to the article, which one is true about “a sweet pea’s coil”?
A. to be like that of a spring
B. to bend all in the same direction
C. to make the stem hard break
D. to make the stem get soft when pulled hard
3.When the sweet pea plant finds something to hold onto, .
A. g-fiber cells on both sides of stem, forcing the stem to bend and coil
B. g-fiber cells on side of stem shrink, forcing the stem to bend and coil
C. g-fiber cells on the stem start to stretch, forcing the stem to bend and coil
D. there are more g-fiber cells on the stems
4.What’s the purpose of the writer in the passage?
A. To tell us why the sweet peas can climb the tree or stick.
B. To display new research allows scientists to understand more about climbing plants.
C. To show us new scientific research about the role of “g-fiber cell”.
D. To tell us the mysterious natural phenomena of some plants.
高二英语阅读理解中等难度题查看答案及解析
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--- What do you think of the service of this hotel?
--- Excellent! They do their best to ______ the guests’ needs.
A. get across B. cater to C. give away D. take over
高二英语单项填空简单题查看答案及解析
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---- ____?
---- Maybe the possible solutions to the air pollution.
A. Do you think what they are talking about
B. Do you think what are they talking about
C. What do you think they are talking aobut
D. What do you think are they talking about
高二英语单项填空简单题查看答案及解析
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---What do you think they are in praise of?
----_________________.
A．ForTomtowinthefirstprize B．Tom’swinningthefirstprize
C．Tomwonthefirstprize D．BecauseTomwonthefirstprize
高二英语单项填空困难题查看答案及解析
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When you buy fresh-cut flowers, do you think about where they came from？You might think they were grown somewhere nearby. The reality, though, is that the cut flower trade is increasingly International. Today, thanks to airplanes and high-tech cooling systems, even the most delicate flower be exported and sold thousands of kilometers away from where it was grown.
The Netherlands handles about 60 percent of the world’s cut flowers. And its auction houses（拍卖行）are very large---Aalsmeer, near Amsterdam, is auction house in the sense that Tokyo is a city, or Everest a mountain. About 120 soccer fields would fill its main building. Nineteen million flowers are sold here on an average day.
The Netherlands is also a world leader in developing new flower varieties. Dutch companies and the government invest a great amount of money in flower research. Their scientists look for ways to lengthen a flower’s vase life, to strengthen flowers to prevent them from being damaged while traveling, and also to strengthen the natural fragrance of the flowers.
There are also many other places with a better climate for growing flowers, and the climate of Ecuador is almost perfect. With predictable rainy periods and 12 hours of sunlight each day, Ecuador’s roses are famous for their large heads and long, straight stems（茎）. Every year, Ecuador sells about 500 million flowers to the U.S. alone. The industry has brought employment opportunities and a stronger economy to the country. “My family has TV now. There are radios.” says Yolanda Quishpe, 20, who picked roses for four years.
To others, the increasingly international nature of the flower trade is very bad news. In recent years local growers in the U.S. faced huge competition from international flower companies, and many lost their businesses. Lina Hale, an independent rose grower said her father had predicted the situation in the 1980s. “I see a train coming down the track,” he warned her, “and it’s coming straight towards us.”
1.What do we know about Aalsmeer?
A.It’s very large.
B.It’s as big as Tokyo.
C.19 million flowers are grown there.
D.60% of the Netherland’s flowers are sold there.
2.What is one aspect of the Netherlands’ flower research?
A.How to increase flower production.
B.How to avoid climate’s effect on flowers.
C.How to speed up the process of flowering.
D.How to keep flowers fresh during transportation.
3.What does the author want to show through Yolanda Quishpe’s words?
A.Flowers from Ecuador are beautiful.
B.Ecuador could grow even more flowers.
C.The flower trade in Ecuador benefits the local.
D.Rose-picking is a very popular job in Ecuador.
4.What Lina Hale’s father said suggested that ______.
A.he was excited to see the train
B.he knew his business would be affected
C.he was sure customers wouldn’t want
D.he thought trains were a new way to deliver flowers
高二英语阅读理解中等难度题查看答案及解析
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—What did your parents think about your decision?
—They always let me do ______ I think I should.
A. when B. that C. how D. What
高二英语单项填空中等难度题查看答案及解析
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I used to think ants knew what they were doing. The ones marching across my kitchen counter looked so confident; I just figured they had a plan, knew where they were going and what needed to be done. How else could ants organize highways, build elaborate nests, launch impressive attacks, and do all the other things ants do?
Turns out I was wrong. Ants aren’t clever little engineers, architects, or soldiers after all --- at least not as individuals. When it comes to deciding what to do next, most ants don’t have a clue. “If you watch an ant try to accomplish something, you’ll be impressed by how awkward it is,” says Deborah M. Gordon, a biologist at Stanford University.
“Ants aren’t smart,” Gordon says. “Ant colonies are.” A colony can solve problems unthinkable for individual ants, such as finding the shortest path to the best food source, assigning workers to different tasks, or defending a territory from neighbors. As individuals, ants might be tiny dummies, but as colonies they respond quickly and effectively to their environment. They do it with something called collective intelligence.
Where this intelligence comes from raises an essential question in nature: How do the simple actions of individual ants add up to the complex behavior of a group? How do hundreds of honey-bees make a critical decision about their hive (蜂巢)if many of them disagree? The collective abilities of such animals --- one of which grasps the big picture, but each of which contributes to the group’s success --- seem miraculous even to the biologists who know them best. Yet during the past few decades, researchers have come up with fascinating insights.
1.The author’s former false impression about ants is that he thought them to be _______.
A. smart B. awkward C. elaborate D. creative
2.Which of the following is TRUE according to the passage?
A. Ants will function as a single body once a decision is made by the commander.
B. Ants are the only species which developed collective intelligence.
C. The ant queen plays a role in managing ant workers besides laying eggs.
D. An individual ant can’t comprehend the whole process of a big movement.
3.The paragraph following the passage will most probably deal with _______.
A. where we can observe such fantastic behavior of ants
B. which is the leading ant in charge of the action
C. how the collective intelligence works
D. what inspiration can be drawn from the collective abilities
高二英语阅读理解困难题查看答案及解析
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–Do you think they have as many books as they’ve described?
--Well, in my opinion, they have few books, if ______.
A. some B. none C. any D. many
高二英语单项填空中等难度题查看答案及解析
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It is what you think about not what you have or what you are doing ______ makes you happy or unhappy.
A.what B.that C.whether D.when
高二英语单项填空中等难度题查看答案及解析
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--- What do you think we can do for our parents?
---You _____ do anything except to be with them and be yourself.
A. don't have to B. oughtn't to c. mustn't D. can't
高二英语单项填空中等难度题查看答案及解析