Mr. Thompson said that 后面接的是一个宾语从句,were part of what中part of what 是表语,而后面的was needed... 又是一个定语从句,修饰what, 因为what本身在从句中又作主语,定语从句中本该有的引导词that或which也...what就是一个SOMETING的意思是吧,后面是省略引导词的定语从句what跟something还不完全一样，在这里what等于the thing that.