1. A: Where's Jack?

      B: He  is  playing football.

2. A: Let's play table tennis.

      B: Sorry. We         are           having dinner now.

3. A: Where are Linda and Kate?

      B: They       are             shopping.

4. A: Are you OK?   

      B: Yes, I        am          having great fun.

5. A: Please help me.

      B: Sorry. I  am   reading a book.

6. A: Can I talk to Lan?                

      B: She isn't at home. She     is               riding her bike.