But why should they sleep deeply at all? Why should a state of such deep immobilization ever have evolved?

但他们为什么要睡得很沉呢？为什么出现如此深度固定？

According to the passage, the immobilization hypothesis fails to account for which of the following facts?

根据文章，不移动假说没能解释以下哪些事实？

And on top of all that, every two days of immobilization, your resting heart rate increase by one beat per minute, eventually plateauing.

其最严重是，只要保持固定不动，每两天，你心脏静息上升每分钟多跳一拍，最后则居高不下。

Prevention of a deep vein thrombosis is also important - compression stockings and frequent calf exercises during long periods of immobilization can help move blood through the veins to prevent stasis.

DVT预防也很重要，弹力袜以及长期制动患者进行规律小腿活动来防止血流瘀滞也是有必要。