例句：

　　They sleep by day and hunt by night.

　　他們白天睡覺，夜晚捕獵。

　　He was a loner by nature and by inclination.

　　他天性不喜交際，且自己也無(wú)意于此。

　　Nocturnal animals sleep by day and hunt by night.

　　夜間活動(dòng)的動(dòng)物白天睡覺晚上獵食。