I came to know it was not easy to easy monwy.中的it必为that行吗?

题目

I came to know it was not easy to easy monwy.中的it必为that行吗?
"必"改为"改".

答案

我想,阁下的原句应该是“I came to know it was not easy to earn money.”吧.
正如上面的朋友说的,it是形式主语,它指代的就是后面的“赚钱不容易”的意思.不能用that.和下面这句"It's necessary for you to be more careful when you cross the road."一样,其中的it也是形式主语.关键是看它是不是指待一件事