读一读,补全对话。 A: Hi, Jack. This is mom. 1._______________ ? B: I'm reading a book. A: 2.________________________ ? B: No, my sister isn't reading. She's playing. A: 3._____________ ? B: My brother is drawing on the floor. A: 4.__________________ ? B: My father is sleeping. A: What? 5.________ ? B: He's in the study.