Complete the questions with the correct form of the Present continuous. Then complete the short answers.
1.A: (they / swim) in the sea? B: No, they . 2. A: (you / listen) to your MP3 player? B: Yes, I . 3 A: (Diana/use) John's computer? B: No, she . 4 A: (Dad / cook) dinner for us? B: Yes, he .