1 Is Mike singing.? No, he isn't
2 Are Mary and Betty swimming? Yes, they are.
3 Is the frog jumping? Yes, it is.
4 Is Masha going to the school? No, she isn't
5 Are Tim and Nick eating breakfast? Yes, they are.
6 Is the parrot flying.? Yes, it is
7 Is Mike doing homework?no, he isn't.