Cemf
abbr. 反電動勢（Counter Electromotive Force）
??? 情景例句
We need a new coffee-table book,
我們需要一本可以擺在客廳的書，
How long are you going to stay here?
你要在這里停留多久？
Let me see the specifications for that.
讓我看看它的規格說明書吧。