Prefractionation
初步分馏
🗣️ 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。
My father always gave an ear to my problems.
家父常常倾听我的问题。
Every solid object will reflect a sound, varying according to the size and nature of the object.
任何固体者反射声音，反射的声音因物体的大小和性质的不同而不同。