Question

Scientists have been puzzled by the phenomenon that migrating birds fly not just in groups all the time, but in "V" formations and they have tried to figure out what benefit birds get from this particular formation. Now, a research group from University of London may have found the answer ― migrating birds fly in a "V" to save energy, according to a study published in the journal Nature.

When a bird flaps(振翅) its wings, it stirs the air around it and causes it to move indifferent directions. Scientist found in the study that the air creates an upward-moving wave at the tips of the wings, which means that if a bird flies around the wingtips of another bird, it can get a boost（抬高） from the rising air and therefore use less energy to stay in the air.

Apart form the "free ride" strategy, scientists were also surprised to observe that migrating birds timed their wing beats and adjusted their positions in a very precise way to maximize the lifting effect while avoiding areas where the air move downward.

"They're able to sense what's going on from the bird in front, where this 'good air' is coming from and now how to position themselves perfectly in it," lead researcher Steven Portugal told BBC.

In fact, the "V" formation has long thought to help birds fly more efficiently(效率搞地). A previous study showed that birds' heart rates went down when they were flying together in a "V" formation. Jet fighters were also found to be able reduce their energy use by up to 18% by staying near the wingtips of other jet fighters. Both of these findings led scientists to suspect that the "V" formation had an efficiency purpose, but until now they still lack proof.

"For scientists, the new study provides an insight into an interesting natural phenomenon. But it could mean even more for aircraft companies — helping them understand how they can imitate that with their plane formations to save fuel, said Portugal."

1.What is the author's purpose in writing this article?

A. To explain how birds benefit from migration.

B. To introduce how migrating birds find their way.

C. To tell some applications of migrating birds' "V" formations.

D. To report new findings about migrating birds' "V" formations.

2. According to the recent study, when birds migrate .

A. they don't change their lead birds during the whole journey

B. they fly in "V" formations to protect themselves against enemies

C. they form the shape of a "V" to make best use of the lifting effect

D. the air they stir around makes it hard for the birds behind to fly fast

3.What is the significance of the new study according to this article?

A. It might inspire aircraft companies to think of ways to improve efficiency.

B. It has proved that the "V" formation can improve in efficiency in many fields,

C. It has led scientists to discover that birds' heart rates go down when they fly in a "V".

D. It shows that the best formation of jet fighters in battle should be a "V" formation.

4. The underlined word "imitate" in the last paragraph most probably means "".

A. useB. copyC. changeD. learn

 

Answer 1

1.D

2.C

3.A

4.B

【解析】本文介紹的是一項(xiàng)新的研究，是關(guān)于候鳥使用V字形飛行的原因。以此對我們的飛機(jī)制造有些啟發(fā)作用。

1. D

【試題解析】推理題。根據(jù)文章主題段第一段最后一句Now, a research group from University of London may have found the answer ― migrating birds fly in a "V" to save energy, according to a study published in the journal Nature.可知本文是對候鳥使用V字形飛行的原因的研究的新的發(fā)現(xiàn)。故D正確。

2.2】 C

【試題解析】推理題。根據(jù)文章第三段Apart form the "free ride" strategy, scientists were also surprised to observe that migrating birds timed their wing beats and adjusted their positions in a very precise way to maximize the lifting effect while avoiding areas where the air move downward.可知候鳥按照V字形飛行是為了更好地利用鳥兒拍打翅膀帶來的lifting的影響，讓飛行的效率更高。故C正確。

3.3】 A

【試題解析】推理題。根據(jù)文章最后2行. But it could mean even more for aircraft companies — helping them understand how they can imitate that with their plane formations to save fuel, said Portugal."可知飛機(jī)制造商可以利用這一研究結(jié)果來提高飛機(jī)飛行的效率。故A正確。

4.4】 B

【試題解析】猜測詞義題。根據(jù)本句But it could mean even more for aircraft companies — helping them understand how they can imitate that with their plane formations to save fuel, said Portugal."可知這一新發(fā)現(xiàn)能夠幫助那些飛機(jī)制造商，更好地理解他們?nèi)绾文７馒B兒的這一飛行特點(diǎn)來改造飛機(jī)以節(jié)省燃料。該該詞是指“模仿”，故B正確。

【長難句解析】

Scientists have been puzzled by the phenomenon that migrating birds fly not just in groups all the time, but in "V" formations and they have tried to figure out what benefit birds get from this particular formation.

【翻譯】科學(xué)家對于這一現(xiàn)象感覺很困惑，候鳥飛行的時(shí)候不僅僅是一直都是一群鳥兒一起飛而且是按照V字形在飛行。他們一直都想知道從這種特殊的飛行模式中鳥兒能夠得到什么樣的好處。

【分析】本句中有一個(gè)同位語從句that migrating birds fly not just in groups all the time, but in "V" formations，對前面的名詞the phenomenon進(jìn)行解釋說明，that在這個(gè)同位語從句中不充當(dāng)任何成分，只是一個(gè)引導(dǎo)詞而已。同時(shí)動(dòng)詞figure后面還有一個(gè)由what引導(dǎo)的賓語從句，what在賓語從句中做主語。