看图完成对话。

1. A: What are they doing? B: They're _______________________. 2. A: What _________________________? B: They're _______________________. 3. A: ______________________________? B: ______________________________. 4. A: ______________________________? B: ______________________________.

1. playing
2. are they doing, sitting
3. What are they doing, They are walking
4. What are they doing,They are running
答案不唯一