Undersurface
n. 下面, 底面\\na. 水面下的
🗣️ 情景例句
when I was about eighteen years old.
那时我差不多十八岁。
When did you know the answer?
你什么时候知道答案？
She tried to play jazz on it!
因为她用它来弹奏爵士乐。