We should allow them to finish the hard work改为被动句怎么改啊?

问题描述:

We should allow them to finish the hard work改为被动句怎么改啊?
我做的是:we should allow the hard work be finished by them.但却是错的.讲讲!

They should be allowed to finish the hard work.意思是:他们应该被允许完成艰难的工作.工作应该是被完成的,
被动语态是be+动词的过去分词,构成的.