while

释义

conj. 当...的时候
n.&a. 一会儿
v. 消磨

例句

1. I haven't seen him for a long while.
   我已经很久没见到他了。
2. While Mary was writing a letter, the children were playing outside.
   玛丽写信时，孩子们在外面玩耍。