Question

    Brown bears have stopped eating salmon（鲑鱼）in favor of elderberries after being forced to make a choice due to climate change. Warming temperatures mean that the berries are ripening earlier than usual, at exactly the same time as the freshwater streams on Alaska’s Kodiak Island are over flowing with salmon.

The island’s brown bears typically feed first on salmon in early summer, followed by elderberries later in the season, in late August and September.

“What you have is a scrambling of the schedule,” said William Deacy, a biologist at Oregon State University that studied the phenomenon.

“It’s essentially like if breakfast and lunch were served at the same time and then there is nothing to eat until dinner. You have to choose between breakfast and lunch because you can only eat so much at a time.”

The study found that during the unusually warm summer of 2014, the bears, which would traditionally kill up to 75 percent of the salmon, were nowhere to be seen near the streams. Instead, they were in the hills busy munching on berries, which contain less protein and therefore take less energy to break down, causing them to gain weight more quickly.

Biologists warned that changes caused by a warming planet were behind the bears’ unusual behavior and could affect the entire ecosystem.

The researchers found that the forests around the streams suffered because the bears’ fish carcasses（残骸）were no longer there to enrich the soil.

“Bears switched from eating salmon to elderberries, disturbing an ecological link that typically fertilizes the ecosystems and generates high death rates for salmon,” the study said. On average, red elderberries are said to be ripening two and a half days earlier every decade. If the pattern continues, they will regularly overlap（重叠）with the salmon by 2070.

1.Brown bears have begun to favor ________ because of the climate change.

A.salmon

B.elderberries

C.warm temperatures

D.fresh water

2.What does William Deacy mean by saying the underlined sentence?

A.Brown bears eat their breakfast and lunch at the same time.

B.We’re facing a hard problem with choosing the meals.

C.Climate change is disturbing the bears’ eating habits.

D.People’s biological clocks are changing regularly.

3.Which of the following words can best describe the phenomenon?

A.Natural. B.Unusual.

C.Amazing. D.Typical.

4.The finding of the study shows us that ________.

A.brown bears may become bigger and bigger

B.there will be a higher death rate for the salmon

C.red elderberries will probably be ripening in summer

D.the changes of bears’ behavior could affect the entire ecosystem

Answer

1.B

2.C

3.B

4.D

【解析】

本文是一篇说明文。文章主要介绍了棕熊行为的变化是受到气候变化的影响，同时棕熊行为的变化也会影响整个生态系统。

1.

细节理解题。根据第一段Brown bears have stopped eating salmon（鲑鱼）in favor of elderberries after being forced to make a choice due to climate change.“由于气候变化，棕熊被迫做出选择，已经停止食用鲑鱼，而青睐于浆果。”可知，由于气候变化，棕熊现在喜欢吃浆果。故选B。

2.

词句猜测题。本句的字面意思是“你所拥有的是时间表的混乱。”再根据下一段It’s essentially like if breakfast and lunch were served at the same time and then there is nothing to eat until dinner. You have to choose between breakfast and lunch because you can only eat so much at a time.“这好比是早餐和中餐一起吃，你一次只能吃那么多，所以你只能吃一餐。”可知，此处的“时间表”指的是饮食方面。所以可以猜测出William Deacy说这句话的意思是“气候变化正在扰乱熊的饮食习惯。”，也就是熊的行为受到了气候变化的影响，与文章开头相呼应。故选C。

3.

推理判断题。根据第六段Biologists warned that changes caused by a warming planet were behind the bears’ unusual behavior and could affect the entire ecosystem.“生物学家警告说，由变暖的行星引起的变化是熊不寻常行为的背后原因，并可能影响整个生态系统。”可知，生物学家认为熊的这种行为是不寻常的。另外，根据文章可知这种现象又是以前没有的，所以我们可以推断出，棕熊的行为变化的这种现象是不同寻常的。故选B。

4.

细节理解题。根据第六段Biologists warned that changes caused by a warming planet were behind the bears’ unusual behavior and could affect the entire ecosystem.“生物学家警告说，由变暖的行星引起的变化是熊不寻常行为的背后原因，并可能影响整个生态系统。”然后，文章又在接下来的三段里举例说明了熊行为的变化是如何影响整个生态系统的。所以可知，这个研究发现向我们展示了：熊行为的变化可能会影响整个生态系统。故选D。