为什么是“I find it difficult to learn English well?"

问题描述:

为什么是“I find it difficult to learn English well?"
这里的it为什么不是it's?不是“it's + adj + to do sth”吗?

I find it difficult to learn English well.
在find/believe/think 的宾语从句中,is可以省略,意思是一样的
如:I thought it difficult to learn English well