China is not〔 〕it used to be 为什么不用that而用what
问题描述：
China is not〔 〕it used to be 为什么不用that而用what
答
what有’所谓的，所说的‘意思，这是一个有what引导的表语从句【一个重要的句型】，而that一般无意。
答
that是表指代，如果你非要用that可以说China is not〔the country that 〕it used to be
答
it used to be what?
答
举个例子你就知道了
Do you know what he knows?
Do you konw the answer that he knows?