He was motionless, all but for one finger that moved up and down in front of his face as if he were marking time with it.

他一动也不动，除了一根手指在他的面前上下摆动,好像在用它标记时间。

耶鲁公开课 - 1945年后的美国小说课程节选

It has units of time, it represents the price of time, and it is something that fluctuates through time in interesting patterns.

这是一种时间的单位,代表着时间价值,利率以它特殊的模式,随着时间上下摆动

耶鲁公开课 - 金融市场课程节选

Some people think this is absolutely vile, some people don't, others are everywhere in between.

有人觉得深闺习俗影响恶劣，有人不觉得，其他人在两者之间摆动。

普林斯顿公开课 - 人性课程节选

So, you see how we are oscillating back and forth?

你可以看到我们如何前后摆动？

麻省理工公开课 - 固态化学导论课程节选

This doesn't mean the object is bobbing up and down.

它不表示物体在上下摆动

耶鲁公开课 - 基础物理课程节选