问题补充：
33.His writing is so confusing that it’s difficult to make out
答案：
what it is = what idea he is trying to express.他想表达的思想/观点.
what- = sth that-/ which-
======以下答案可供参考======
供参考答案1:
What指前面的一长串~
供参考答案2:
不是强调句，首先整个句子是so--that*---
what一方面做make out的宾语，同时是express的宾语
