I find-----not easy to learn math well A,this B,that C,what D,it

I find-----not easy to learn math well A,this B,that C,what D,it
I find-----not easy to learn math well A,this B,that C,what D,it

I find-----not easy to learn math well A,this B,that C,what D,it
选D
意思是我发现学好数学不简单
句型为find it +adj+to do

答案选D
I found + it +形容词+ to do sth，这是一个固定句型，意思是：我发现做某事很怎么样。
题目的意思是：我发现学好数学不容易。
it是做形式主语，真正的主语是后面的to do sth.