Đáp án:
Ex 7:My best friends are going to Spanish next year.
       => What's your best friends going to do next year?
        I am thinking about you. 
       => What are you thinking about?
       Tom's sister is studying homework at the moment.
       => What is Tom's sister doing at the moment?
Ex 8:
Are you listening to me?--> Yes, I do.
Are your cousins singing?--> No, they don't.
Are you watching a new film?--> No, am not.
Is Sara doing homework?--> No, she doesn't.
Is Bob playing rugby?--> Yes, he does.
Are your parents cooking dinner?--> Yes, they are.
Ex 9:
Bob is walking the dog.
Matt is taking a shower.
They are eating dinner.
She is teaching.
Kim is swimming.
Laura is playing.

Ex 8:
- => Yes, I AM                                                                     - => No, she IS
- => No, they ARE                                                              - => Yes, he IS
- => No, I AM                                                                     - => Yes, they ARE

Ex 9:
-Bob is walking the dog.
-Matt is taking a shower.
-They are eating dinner.
-She is teaching.
-Kim is swimming.
-Laura is playing.