Iff
[計] 如果僅僅, 當且僅當, \等價\
??? 情景例句
Not at all. It's my pleasure.
不客氣。這是我的榮幸。
Could you give us detailed descriptions of the capabilities of your product?
請你把你們產品的性能給我們詳細說明一下好嗎？
What bad weather! I don't like the snow.
天氣糟透了！我不喜歡下雪天。