What the police want to know is when you entered the room.请哪位老师帮我分析下这个句子的结构,前面为什么用what,省略可否.
问题描述：
What the police want to know is when you entered the room.
请哪位老师帮我分析下这个句子的结构,前面为什么用what,省略可否.
答