Valvetrain
气门
🗣️ 情景例句
I want to send this letter to China, by air mail.
我想把这封信航空邮到中国。
Never deter till tomorrow that which you can do today.
今日事须今日毕，切勿拖延到明天。
That was a long time ago,wasn't it?
那是好久以前的事了。是吗？