You cannot have a spring pulled only at one side, because then it will then accelerate with infinite acceleration in that direction.

你不可能对弹簧只施加一边的拉力,因为那样的话弹簧就会以无穷大的加速度加速,就在这个方向上

耶鲁公开课 - 基础物理课程节选

Maybe you're talking with a friend about where you should go for spring break vacation,

假如你在跟一个朋友讨论你们该去哪里过春假。

I've already 课堂 - SpeakingMax英语口语达人