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问题 连线题

将下列食物与其作用搭配起来，并填在相应的括号里。

①---（ ） ②---（ ） ③---（ ） ④---（ ） ⑤---（ ）

答案

①---（B ） ②---（A ） ③---（C ） ④---（D ） ⑤---（E ）

不定项选择

当晶体的温度正好是熔点或是凝固点时，它的状态为[ ]

A．可能是固态、液态共存

B．一定是液态

C．可能是固态

D．可能是液态

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单项选择题

The population of elephant seals, reduced by hunting to perhaps a few dozen animals early in this century, has soared under federal protection during the last few decades. However, because the species repopulated itself through extensive inbreeding, it now exhibits a genetic uniformity that is almost unparalleled in other species of mammals, and thus it is in far greater danger of becoming extinct than are most other species.
Given the information in the passage above, which of the following is most likely the reason that other species of mammals are leas likely than elephant seals to become extinct ？（）

A．Other species of mammals have large populations, so the loss of a few members of the species is not significant.

B．Other species of mammals have increased their knowledge of dangers through the experience of generation after generation of animals.

C．In other species of mammals, hunters can readily distinguish between males and females or between young animals and adults.

D．In other species of mammals, some members of the species am genetically better equipped to withstand a disease or event that destroys other members of the species.

E．Other species of mammals have retained habits of caution and alertness because they have not been protected as endangered species.
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