登录
B
What do bears like to eat? You might think their favorite foods are fish and honey. But some bears eat leftover (剩饭) human food that they find in the trash. However, it turns out that this is not very good for them.
The scientists then looked at how long the bears were hibernating (冬眠) during the winter. Scientists from the University of Wisconsin studied wild black bears in the state of Colorado in the US. After studying the bears’ diets, they found that some of the bears were eating human food that had been thrown away.
What they found was not good news for the bears. They found that bears that ate leftover human food tended to hibernate for shorter periods of time. Some of them hibernated 50 days fewer than bears who ate a natural diet. Unfortunately, bears that hibernate for shorter periods of time tend to have shorter lifespan (寿命) than other bears.
This is because they end up having shorter telomeres (染色体端粒). As animals get older, their telomeres naturally shorten. As the telomeres get shorter, the animals start to show more signs of aging. Therefore, if the bears have shorter telomeres to begin with, they will age faster. However, it is not clear how the shortened telomeres are linked to shorter hibernation periods.
There is not a “definitive (确定的)” link between bears eating more human food and shortening telomeres, according to Rebecca Kirby from the university. However, Kirby did describe the evidence (证据) she had so far as being “suggestive (提示性的)”, according to Science News.
( ) 5. The scientists who did the study tried to find out ______.
A. what bears eat if there is no food in the wild
B. how long bears can hibernate
C. how much bears can eat
D. if it is good for bears to eat human food
( ) 6. According to the scientists, bears that eat human food ______.
A. will act more like humans
B. may live shorter lives
C. hibernate for longer time
D. get sick more easily
( ) 7. Paragraph 4 is written to ______.
A. describe a similar study
B. explain the findings
C. describe why bears like to eat leftover food
D. tell readers how long bears can live
( ) 8. According to Rebecca Kirby, the findings from the study ______.
A. have been proven true
B. are not definitive
C. are not supported by evidence
D. are hard to believe
What do bears like to eat? You might think their favorite foods are fish and honey. But some bears eat leftover (剩饭) human food that they find in the trash. However, it turns out that this is not very good for them.
The scientists then looked at how long the bears were hibernating (冬眠) during the winter. Scientists from the University of Wisconsin studied wild black bears in the state of Colorado in the US. After studying the bears’ diets, they found that some of the bears were eating human food that had been thrown away.
What they found was not good news for the bears. They found that bears that ate leftover human food tended to hibernate for shorter periods of time. Some of them hibernated 50 days fewer than bears who ate a natural diet. Unfortunately, bears that hibernate for shorter periods of time tend to have shorter lifespan (寿命) than other bears.
This is because they end up having shorter telomeres (染色体端粒). As animals get older, their telomeres naturally shorten. As the telomeres get shorter, the animals start to show more signs of aging. Therefore, if the bears have shorter telomeres to begin with, they will age faster. However, it is not clear how the shortened telomeres are linked to shorter hibernation periods.
There is not a “definitive (确定的)” link between bears eating more human food and shortening telomeres, according to Rebecca Kirby from the university. However, Kirby did describe the evidence (证据) she had so far as being “suggestive (提示性的)”, according to Science News.
( ) 5. The scientists who did the study tried to find out ______.
A. what bears eat if there is no food in the wild
B. how long bears can hibernate
C. how much bears can eat
D. if it is good for bears to eat human food
( ) 6. According to the scientists, bears that eat human food ______.
A. will act more like humans
B. may live shorter lives
C. hibernate for longer time
D. get sick more easily
( ) 7. Paragraph 4 is written to ______.
A. describe a similar study
B. explain the findings
C. describe why bears like to eat leftover food
D. tell readers how long bears can live
( ) 8. According to Rebecca Kirby, the findings from the study ______.
A. have been proven true
B. are not definitive
C. are not supported by evidence
D. are hard to believe
答案
5. 答案：D
解析：文章第一段结尾提到 “However, it turns out that this is not very good for them.”，随后科学家研究了熊的冬眠时长和饮食的关系，目的是验证吃人类食物对熊是否有害。
6. 答案：B
解析：第三段明确指出 “Unfortunately, bears that hibernate for shorter periods of time tend to have shorter lifespan (寿命) than other bears.”，说明吃人类食物的熊冬眠时间更短，进而寿命可能更短。
7. 答案：B
解析：第四段解释了为什么冬眠时间短会导致寿命缩短 —— 因为染色体端粒更短，衰老更快，这是对前文研究发现的原理性解释。
8. 答案：B
解析：最后一段提到 “there is not a 'definitive (确定的)' link” 以及 “Kirby did describe the evidence (证据) she had so far as being'suggestive (提示性的)'”，说明研究结果目前并非完全确定的结论。
