单项选择题


A．decisive
B．determinant
C．essential
D．crucial
<上一题 目录 下一题>
热门 试题

单项选择题
Compare with dreamless sleep, deep dream sleep is ______.
A．not the result of natural selection
B．less likely to appear to moneys
C．more protective to the animals
D．at a higher stage of evolution
单项选择题
According to some scientists' research findings, dolphins seldom sleep because ______.
A．of their stupidity
B．of their vulnerability
C．there are possible dangers in the ocean
D．aquatic mammals do not need sleep
相关试题