Optional nature
[法] 任择性, 非强制性, 任意性
🧩 词语组成解析
🗣️ 情景例句
My stomach growls at me when I'm hungry.
我的肚子在咕噜咕噜地向我发牢骚呢！
Pick up the receiver and deposit a coin in the slot.
拿起听筒和放一个硬币到投币口。
It seems that the further cats fall, the less they are likely to injure themselves.
看起来，猫跌落的距离越长，它们就越不会伤害自己。