If I am an inertial observer, another person moving relative to me at constant velocity will also be an inertial observer.

如果我是惯性观察者,那另一个相对于我做匀速运动的人,也是一个惯性观察者

耶鲁公开课 - 基础物理课程节选

when other people that might not have been involved with the sport wouldn't really know what to do.

而或许没参与过这项运动的人连做什么都不知道。

体育相片的魅力 - SpeakingMax英语口语达人

I mean all those of you doing sports here-- and it's most of you in this room who are doing athletics, who go for a run, you rely on the law of gravity.

你们中喜欢运动的-,教室里多数人都做运动，跑步时需要万有引力定律。

哈佛公开课 - 幸福课课程节选