It is conceivable that animals who are too stupid to be quite on their own initiative are,during periods of high risk,immobilized by the implacable arm of sleep.那by the implacable arm of
问题描述：
It is conceivable that animals who are too stupid to be quite on their own initiative are,during periods of high risk,immobilized by the implacable arm of sleep.
那by the implacable arm of
答
这是一个复合句.that引导的强调句,animals后面又有定语从句.句末又有一个伴随状语.