可以有三种不同的改法.
1.对Kangkang 部分提问：Who meets Jane and Helen at the school gate?
2.对Jane and Helen 部分提问：Who/Whom does Kangkang meet at the school gate?
3.对at the school gate 部分提问：Where does Kangkang meet Jane and Helen?
4.没有要求对划线部分提问：When / Why does Kangkang met Jane and Helen at the school gate?
应该全了.