单项选择题

Predators are _______.

A．able to prey even when they are in deep dream sleep
B．more likely to experience dream sleep
C．incapable of preying when immobilized by dreamless sleep
D．good at preying on stupid animals

<上一题目录下一题>

热门试题

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

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