《2025年高中同步单元滚动强化卷高中英语必修第二册北师大版》

D
Most squirrels don’t hibernate(冬眠). Instead, they store food for the cold season and spend the winter in their nests. But the 13-lined ground squirrel, one species of squirrel in the US Midwest, is not the case. For up to 8 months, the tiny mammals won’t eat or drink anything at all and the heart rate, metabolism(新陈代谢),and body temperature dramatically drop during their long rest, which is similar to bears and other hibernating animals.
To find out how the hibernating squirrels hold back their thirst, a powerful force that could potentially wake them up, and researchers measured the blood fluid of dozens of squirrels. Generally, a high blood concentration(血液浓度)makes animals, including humans, feel thirty. The sleeping squirrels’ blood concentration was low, preventing them from waking up for a drink. Even when researchers woke up the torpid(迟钝的)squirrels, they wouldn’t drink a drop until the team artificially increased the concentration of their blood serum(血清).
Next, the researchers wanted to know how the squirrels’ blood concentration dropped so low. Perhaps the squirrels drank a lot of water before hibernation to dilute(稀释)their blood, the researchers thought. But when they filmed squirrels preparing for their winter snooze, they found the animals actually drank less water than they normally did.
Instead, chemical tests revealed the squirrels adjust their blood concentration by getting rid of electrolytes(电解质)like sodium(钠)and other chemicals like glucose(葡萄糖)and urea(尿素)and storing them elsewhere in the body(possibly in the bladder), the researchers reported last month in Current Biology. The finding could also explain how other hibernating animals stay containing water.
This new knowledge might one day help humans with conditions such as diabetes(糖尿病),or astronauts(宇航员)who have launched on long space flights. Unfortunately, even if people can figure out how to drop their blood concentration, it’s unlikely they’ll ever be as cute as sleeping squirrels.
32. What do we know about the 13-lined ground squirrels?
A. They don’t hibernate like many other squirrels.
B. They are endangered species in the US Midwest.
C. They can live for months without water during hibernation.
D. Their heart rate and body temperature are extremely abnormal.
33. Why don’t the hibernating squirrels feel thirsty?
A.They have high blood concentration.
B. They have low blood concentration.
C. They have low body temperature.
D. They have high heart rate.
34. How could hibernating squirrels change their blood concentration?
A.By drinking much water before hibernation.
B. By not eating anything during hibernation.
C. By drinking less water than they normally do.
D. By removing certain chemicals and storing them somewhere.
35. What is the author’s attitude towards the new findings?
A.Objective. B. Positive.
C. Disappointed. D. Uncaring.

答案： 32.C 33.B 34.D 35.B