例句：

　　Unless I'm mistaken, she was back at work yesterday.

　　除非是我記錯了，她是昨天回來(lái)上班的。

　　He resolutely refused to speak English unless forced to.

　　除非被逼迫，他堅決拒絕說(shuō)英語(yǔ)。

　　Why did you need a room unless you were up to something?

　　除非你要搗什么鬼，不然為什么需要一個(gè)房間呢？