题目内容
C
★★★★★
A study conducted in the Svalbard Archipelago of;Norway showed the first recorded case of polar bears seeking out white-beaked dolphins(白喙斑纹海豚) for prey(猎物) . Warming waters have allowed the dolphins to travel north to an area they would normally avoid until summertime. “It is likely that new species are appearing in the diet of polar bears due to climate change because new species are finding their way north,” study author Jon Aars said.
Arctic waters have warmed at a rate twice that of southern waters,putting the ice-loving bears in trouble. Polar bears typically sit on large pieces of ice to hunt swimming seals,but without the platform of ice to sit on,the bears have to look elsewhere for food. Two ice-free winters attracted the dolphins into the Arctic region,where their food has also shown up thanks to warm water. But a sudden influx (汇集)of ice trapped the dolphins,making them easy prey for hungry plar bears.
The scientists from the Norwegian Polar Institute first discovered this eating habit in April,2014 and documented another five cases in the following year. Most of the bears appeased well-fed,although one was visibly thin and found covering a dead dolphin with ice as a means to hide his food source from other animals —another strategy that scientists had not yet seen before.
It' s unlikely that there are enough dolphins to feed the large population of polar bears. And as the bears were only able to hunt the dolphins because of a sudden storm,their consumption could be a fluke(使幸) .
Polar bears living in Canada and Alaska have been found traveling north to live in the icy regions they need,but Svalbard is about as far north as it gets before the water becomes too deep to serve as a livable habitat,leaving the bears with nowhere else to go.
9. What does Jon Aars think is to blame for polar bears' eating dolphins?
A. Loss of habitat: B. No other prey.
C. Warmer climate. D. Shorter summertime.
10. What do we learn about today's polar bears from Paragraph 2 ?
A. They fmd it harder to hunt seals.
B. They have more food than before.
C. They face more competitors than before.
D. They are troubled by a sudden influx of ice.
11. It is very rare for a polar bear to.
A. appear well-fed
B. get nothing to eat
C. hide food from other animals
D. share food with other polar bears
12. After polar bears reach Svalbard,they .
A. get no dolphins to eat
B. cannot go any further northward
C. hardly want to go anywhere else
D. make it a comfortable livable habitat
C篇
科学家发现北极熊捕食白喙斑纹海豚,这主要是因为全球气候变暖造成的。
9. C. 细节理解题。根据第一段中的it is likely that new species are appearing in the diet of polar bears due to climate change because new species are finding their way north 可知,Jon Aars 认为北极熊捕食海豚是因为气候变暖造成的。
10. A. 推理判断题。根据第二段中的polar bears typically sit on large pieces of ice to hunt swimming seals,but without the platform of ice to sit on,the bears have to look elsewhere for food 可知,如今北极熊比以往更难捕食海豹了。
11. C. 细节理解题。根据第三段中的one was visibly thin and found covering a dead dolphin with ice as a means to hide his food source from other animals another strategy that scientists had not yet seen before可知,北极熊堙藏食物非常罕见。
12. B. 推理判断题。根据末段中的but Svalbard is about as far north as it gets before the water becomes too deep to serve as a livable habitat,leaving the bears with nowhere else to go 可知,北极熊到了 Svalbard之后就无法再继续向北寻找栖息地了。