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问题 单项选择题

中国一所高校原有学生2000人，后与美国一所高校交换留学生，中国高校选出5%的学生派往美国，同时美国高校也选出20%的学生派往中国。现在两所高校的在校生人数相同，那么美国高校原有学生( )人。

A．3600

B．3000

C．2800

D．2500

答案

参考答案：B

解析： 设美国高校原有学生人数为x人，根据题意可知： 2000-2000×5%+20%x=(2000+x)÷2， 解得x=3000，即美国高校原有学生3000人。答案为B。

单项选择题

因肺结核引起的支气管扩张，湿啰音最常见的部位是

A．双肺弥漫

B．腋窝部

C．肺底部

D．肩胛问区

E．肺尖部
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单项选择题

Research on animal intelligence always makes me wonder just how smart humans are. (91) the fruitfly experiments described in Carl Zimmer’s piece in the Science Times on Tuesday. Fruit flies who were taught to be smarter than the average fruit fly (92) to live shorter lives. This suggests that (93) bulbs burn longer, that there is an (94) in not being too terrifically bright.
Intelligence, it (95) , is a high-priced option. It takes more upkeep, burns more fuel and is slow (96) the starting line because it depends on learning—a gradual (97) —instead of instinct. Plenty of other species are able to learn, and one of the things they’ve apparently learned is when to (98) .
Is there an adaptive value to (99) intelligence That’s the question behind this new research. I like it. Instead of casting a wistful glance (100) at all the species we’ve left in the dust I.Q. wise, it implicitly asks what the real (101) of our own intelligence might be. This is (102) the mind of every animal I’ve ever met.
Research on animal intelligence also makes me wonder what experiments animals would (103) on humans if they had the chance. Every cat with an owner, (104) , is running a small-scale study in operant conditioning, we believe that (105) animals ran the labs, they would test us to (106) the limits of our patience, our faithfulness, our memory for terrain. They would try to decide what intelligence in humans is really (107) , not merely how much of it there is. (108) , they would hope to study a (109) question. Are humans actually aware of the world they live in (110) the results are inconclusive.

A．Suppose

B．Consider

C．Observe

D．Imagine
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