He"s never seen the president before.添加反意疑问句his mother is a (professor) in a university.对打括号的地方提问Did the boys throw the volleyball on the playground?变为被动语态The baby kept on crying until he saw his mother.改写同义句

He"s never seen the president before, has he?
What is his mother (in a university)? 对打括号的地方提问
Was the volleyball thrown by the boys on the playground?变为被动语态
The baby didn't stop crying until he saw his mother.改写同义句

1 ```````has he
2 what is his mother do in a university
3 the volley was thrown the boys on the playground
4 when the baby saw his mother ,he was stopping to cry

①He's never seen the president before,does he?②What does his mother do in a university?③Did the volleyball on the playground are thrown by the boys?④The baby stopped crying when he saw his mother....

Have not he ever seen the president before?
what's his mother
the volleyball was played by the boys on the playground
when the baby sea his mother ,he stopped crying