The trouble is that的用法和樣例：
例句
- His blindness is a great trial to him.
眼睛瞎對他來(lái)說(shuō)是非常麻煩的事。 - Knave is usually a person who gets into trouble.
一個(gè)無(wú)賴(lài)往往意味著(zhù)他是一個(gè)帶來(lái)麻煩的人。 - The difficulty is to know what we mean by a virus.
困難在于懂得病毒指的是什么。 - The difficulty lies in their poor health.
困難在于他們的健康狀況都不好。
