3. Is Ann cutting the grass? Yes, she is
4. Are the children kniting? No, they aren't. They're going to school
5. Are the dogs chasing a cat? Yes, they are
6. Is the postman delivering letters? Yes, he is
7. Is Grandmother standing by the gate? No, she isn't. She standing on chair
8. Is Gransfother write a letter? No, he isn't. He reading a newspaper