sleep protects us only from the sort of trouble that comes looking for us.So we sleep well when we are in familiar, safe place, but we sleep lightly, if at all ,when we fear that bears will nose into the tent
Surely cats do not need five times as much repair and restoration as horses do. But cats can afford to have long periods of inactivity because they spend little time eating and are unlikely to be attacked while they sleep.
they eat is very low in enery value.
怎么翻译的？
參考答案:睡眠会根据我们所处的环境来保护我们.所以当我们在熟悉,安全的地方睡觉时会睡的很沉,而当我们对多处环境不太放心时就会睡的比较浅.
毫无疑问猫不需要象马一样进行多达 五次的补给和休整.猫可以长期处于不活动状态,因为它们花很少时间进食,也不喜欢在睡觉时受到攻击.
他们吃的是低能量的食物.
