题目内容：

I have learned from my bitter experience______we don't know _____we've got until it's gone
A that；that
B what；what
C that； what
D which；that
为什么呢?

优质解答

前一空that引导的是宾语从句,that 没有实在意义；后一空what 引导的也是宾语从句,what 连接从句,同时又是从句中have got 的宾语

追答：

句意:我从我痛苦的经历中了解到，直到我们拥有的东西失去了，我们才知道。