Question

    Every year migratory（迁徙的） bats travel from Mexico to Bracken Cave, where they spend the summer consuming insects that would otherwise hungrily eat common food crops. But the bats have been showing up far earlier than they did two decades ago.

In a study, scientists at Rothamsted Research, used radar data from 160 U.S. weather stations to analyze activity in the Texas bat colony from 1995 through 2017. They discovered the creatures were leaving their winter quarters in Mexico earlier and reproducing sooner. They were also astonished to find increasing numbers of bats overwintering（过冬）at Bracken Cave instead of heading back to their cold weather quarters in Mexico. Overwintering is a sign that warmer temperatures change the bats' annual rhythms, Rothamsted biologist Phillip Stepanian says.

A separate study of migratory bats in Indiana, published last year, found that temperature variations affected arrival and departure times-likewise hinting at the potential influence of climate change. Joy O'Keefe, a biology professor and co-author of that study, says early arrival at their summer habitats could expose these bats to cold snaps（寒流）, and they could freeze to death.

Joy O’Keefe and her colleagues also found that changing bat migration times can also clash with rainfall patterns. Many insects that bats eat breed in seasonal lakes and puddles. If the bats arrive too early to benefit from summer rainfall and the resulting abundance of insects, they may struggle to feed their pups（幼崽） or skip reproduction altogether, O’Keefe says. She fears this shift could cause Midwestern bats to decrease toward extinction, which would be bad news for humans. “Declines in bat populations could have severe effects for crop success,” she says, adding that bats also “control significant disease vectors, such as mosquitoes.”

However, scientists are not certain that climate change alone is causing the Bracken Cave bat colony to migrate earlier. They have found a direct link between seasonal temperatures and bird migration, but bats are also influenced by factors such as changes in wind speed and direction. And there are other complications. “Bats are mysterious little animals that move mostly at night and are difficult to observe and track ,”  Stepanian says. “We have this conceptual picture of what might be happening, but really tying it to the cause is the next step.”

1.What is the best title for the passage?

A.Bats’ habitants B.Endangered bats

C.Bats’ migration D.Bats, our good friends

2.Scientists at Rothamsted Research found that ______.

A.bats prefer heading back to Mexico B.bats delay their reproduction

C.warming affects bat migration D.radar can be used to observe bats

3.Joy O’Keefe discovered that ______.

A.bats are used to living in rainfall seasons

B.bats’ earlier migration might harm farming

C.insects' reproduction helps to spread disease

D.insects shortage makes bats reproduce earlier

4.What does the underlined word they refer to?

A.Insects. B.migration times.

C.Bats. D.lakes and puddles.

5.What does the last paragraph want to tell us?

A.Wind speed and direction affect bats.

B.It is difficult to observe and track bats.

C.Climate change makes bats migrate earlier.

D.Further research on the cause is necessary.

Answer

1.C

2.C

3.B

4.C

5.D

【解析】

这是一篇说明文。作者介绍了蝙蝠迁徙提前的这种现象，然后分析了这种现象可能导致的后果，最后分析了可能导致蝙蝠迁徙提前的原因。

1.主旨大意题。根据第一段中Every year migratory bats travel from Mexico to Bracken Cave, where they spend the summer consuming insects that would otherwise hungrily eat common food crops. 每年，迁徙的蝙蝠都会从墨西哥迁徙到布兰肯洞穴，在那里度过一个夏天，捕食昆虫，否则这些昆虫就会贪婪地吃掉常见的粮食作物。可知，文章先提出蝙蝠迁徙提前的这种现象，再通读全文，然后分析了这种现象可能导致的后果，最后分析了可能导致蝙蝠迁徙提前的原因。所以短文的最佳标题是“蝙蝠的迁徙”。故选C项。

2.细节理解题。根据第二段中最后一句话Overwintering is a sign that warmer temperatures change the bats' annual rhythms, Rothamsted biologist Phillip Stepanian says.罗斯泰德的生物学家菲利普·斯捷潘尼安说，越冬是气温升高改变蝙蝠年度节律的一个标志。可知，洛桑研究中心的科学家发现，气候变暖影响蝙蝠迁徙。故选C项。

3.细节理解题。根据第四段中If the bats arrive too early to benefit from summer rainfall and the resulting abundance of insects, they may struggle to feed their pups（幼崽） or skip reproduction altogether,… “Declines in bat populations could have severe effects for crop success,” she says, …奥基夫说，如果蝙蝠来得太早，无法从夏季的降雨和由此产生的大量昆虫中受益，它们可能难以喂养幼仔，或者干脆不进行繁殖。……她说：“蝙蝠数量的减少可能会对作物的收成产生严重影响。”……可知，蝙蝠迁徒时间的改变也会与降雨模式发生冲突，蝙蝠以季节性繁殖的昆虫为食，而他们过早地迁徙会导致喂养幼仔的困难，或者跳过繁殖期，这将导致蝙蝠数量减少，害虫增加，从而对农作物产生影响。故选B项。

4.词义猜测题。根据第三段中划线词所在句Joy O'Keefe, a biology professor and co-author of that study, says early arrival at their summer habitats could expose these bats to cold snaps（寒流）, and they could freeze to death. 生物学教授、该研究的合著者乔伊·奥基夫(Joy O’keefe)说，提早到达它们的夏季栖息地可能会让这些蝙蝠遭遇寒潮，它们可能会冻死。由could expose these bats to cold snaps可以猜测代词they指代的是bats（蝙蝠）。故选C项。

5.推理判断题。根据最后一段中可知，科学家们不确定仅仅是气候变化导致蝙蝠迁徙提前， 蝙蝠还受到风速和风向等因素的影响。根据最后一句话“Bats are mysterious little animals that move mostly at night and are difficult to observe and track ,” Stepanian says. “We have this conceptual picture of what might be happening, but really tying it to the cause is the next step.”可知， 蝙蝠是一种神秘的小动物，它们大多在夜间活动，很难被观察和追踪。“我们对可能发生的事情有一个概念性的认识，但真正将其与原因联系起来是下一步的事。由此判断出对蝙蝠迁徙提前的原因还需要进一步的研究。故选D项。