单项选择题

Calhoun stabilized the rat population ______.

A．when it was double the number that could live in the enclosure without stress
B．by removing young rats
C．so that there was a constant number of adult rats in the enclosure
D．All of the above are correct

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热门试题

单项选择题

In the passage, the author mentioned: Eskimo words are highly inflected , this probably means

A．Eskimo words are full of forms
B．Eskimo words are difficult to spell
C．Eskimo words are numerous
D．Eskimo words are hard to understand

单项选择题

Some of the evidence about language in the passage is taken from the observations of ______.

A．linguists
B．Eskimos
C．businessmen
D．an explorer