we found this problem difficult to solve solve为什么不用被动

we found this problem difficult to solve solve为什么不用被动 but he found the problem difficult to solve I find it difficult to solve this problem .(改为复合句) this is the problem very difficult to solve The problem is easy to solve.为什么用to solve Help me to solve this problem It difficult for him to solve this problem alone.改同义句 He has ___ a little difficult for me to solve this problem. A. That Enougu__ said on how to solve this difficult problem in such We found________ the problem.A it is difficult to solve B it 问个英语问题.求教.The problem is much too difficult to solve.为什么不是To the problem is difficult to be solved 为什么solve要是过去式