We find it impossible to work out the problem by ourselves

We find it impossible to work out the problem by ourselves we find (it) impossible to finish the work in a week.为什么用it? I find that it it hard for him to work out the problem.句型转换 It is very c__ that we have to finish the work by ourselves I don’t think we can find a new day to work out the problem. most of us find it d_____ to work out the maths problem 改为同义句I find that it is hard for him to work out the problem. I find the problem difficult to work out. I find difficult to work out the problem. it is ——for them to work out the problem by themselves 为什么填e I found it impossible to work out this maths problem 不加be动词也 So diffcult did I find it to work out the problem.这个句子结构帮我分析