1.on and off 开和关，引申为“断断续续，陆续”

同类型的表达方式有 come and go 来来回回

The old man standing against an oak tree had viewed many people came and went.

依着树站着的老人，目睹过好多的人来人往的沧桑。

2.individual adj.个人的，个体的

Individual action coming together can make a huge difference in history.

单个人的行为汇集起来就能强大到足够改变历史。

3.coach n.& vt.教练；执教

The one who coached me is not a good coach, for he always make a hog of himself.

我的教练，不是个好教练，因为他总是很邋遢。