Optional nature
[法] 任择性, 非强制性, 任意性
🧩 词语组成解析
🗣️ 情景例句
Exploring outer space is a challenge to mankind.
探索外层空间是一项向人类发出的挑战。
Skiing is such a difficult sport that it's more work than play.
滑雪是非常困难的运动，真所谓工作高于游戏呀。
As the thieves were trying to get away in their car, Roy drove his bus into the back of it.
当那两个小偷企图乘车逃跑时，罗伊驾驶他的公共汽车撞在了那辆车的后尾上。