The problem is very hard,I don't know how to work out._____

The problem is very hard,I don't know how to work out._____ i don't know how to work out the math problem 同义句 To work out the problem is very hard .(同一句) _____ is very __ The maths problem is so hard,I really don't know ____.A.how 选择填空（）1. I don’t know（）work out the problem . It’s too hard I don't know how to -------------the problem 单项选择 A work at The math problem is so difficult,I don't know __ A how to do To work out the problem is very hard 的同义句答案 快 回答 the math problem is too hard to work ------out how can I work out the problem _____(easy) 改为同义句I find that it is hard for him to work out the problem. The maths problem is so hard.I really don't know ______.