translation.en: Student 4l: [I decided to] do the shot put and the sponge ball because they're two totally different weights, and if you drop them at the same time, maybe they'll drop at the same speed.
translation.zh: 一个是铅球，一个是海绵球 两个的重量完全不同 假如同时扔下去 也许它们的速度是一样的