which

Which book do you want to read?

用法提示：which 在此作形容词，用于疑问句，询问从一组书籍中具体选择哪一本。

I can't remember which movie we saw last week.

用法提示：which 在此作形容词，引导宾语从句，指代特定的一部电影。

The car which is parked outside is mine.

用法提示：which 在此作关系形容词，引导定语从句，修饰先行词 car，表示特定的一辆车。