麻烦解释下为什么……
1.Many of the creatures in Rowling's world are not real, and much of____happens is strange.
A.which B.that C.what D.it
2._____is known to us all is that the old scientist,for_____life was hard in the past,still works very hard in his eighties.
A.As;whom B.What;whom C.It;whose D.As;whose
(这一题是考查名词性从句和定语从句的,可我搞不懂到底怎么区分这两个从句,很是不明白为什么第一个空的答案是what,麻烦解释下)