Useful length
[机] 有用长度
🧩 词语组成解析
🗣️ 情景例句
I'm late for dinner at my house.
我回家吃晚饭要迟到了。
I will take an elevator.
我将去搭电梯。
The rope had been cut, so it was obvious that the lamb had been stolen.
绳子被人割断，很明显小羔羊是被人偷走了。