将下列句子改为主动语态1.Has the work been finished by them?这个我真是一点儿都不会,

将下列句子改为主动语态
1.Has the work been finished by them?
这个我真是一点儿都不会,问句的主动,被动要怎么改?
2.Her brother is being operated on by the doctor.
我改的:The doctor is being operate on her brother.
觉得不太对劲,到底是the doctor is opertating on her brother还是上面那个啊?
3.Children should be taken good care of.
我改的：You should take good care of children.
4.The baby was made to stop crying by Ling.
我改的：Ling was made the baby to stop crying.
5.I was given a pen by Jim a moment ago.
我改的：Jim gave me a pen a moment ago.
今天刚学被动语态,做习题的时候发现有点小难度.而且不确定自己的对错...麻烦大家帮我回答一下我不会的和检查一下我做了的,并指出说明一下.