Unimolecular
a. 單分子的
??? 情景例句
Dear Mr. Lee.
親愛的李先生。
Everything has its time and that time must be watched.
任何事情都有好的時機，不要隨意放過。
When you type a letter, the writing appears on a screen in front of you and is recorded onto a computer disk.
當你打一封信時，字跡出現在你前面的屏幕上并顧在電腦的磁盤里。