Gums
n. 牙龈, 树胶；牙床（gum复数形式）
🗣️ 情景例句
How much extra do I have to pay for that?
我还要另外付多少？
The phone seems to be out of order.
电话好像出故障了。
only of metal, which wears away by friction.
而是由金属组成，而金属可以随着磨擦而磨损殆尽。