通读下面的对话，然后根据上下文补全对话内容。
A: Good afternoon, Miller! 小题1: ?
B: I’m drawing a horse.
A: A horse? Can you let me have a look?
B: 小题2: . Here you are.
A: Oh, the horse looks very nice. Do you often draw in your free time?
B: 小题3: .
A: Do you like drawing?
B: Yes. I like drawing very much.
A: 小题4: ?
B: Because it’s very interesting. And my art teacher is very kind to me.
A: 小题5: ?
B: I have an art lesson once a week.
小题1:What are you doing?
小题2:Sure/Certainly/Of course/No problem
小题3:Yes, I do.
小题4:Why
小题5:How often do you have an art lesson?
小题1:根据答语I’m drawing...可知，问的是“你正在做什么”。故填What are you doing?。
小题2:根据Here you are“给你”可知，答语是肯定的。故填Sure/Certainly/Of course/No problem。
小题3:根据下面的对话可知，B喜欢画画，也经常利用空闲时间画画。故答语是肯定的。故填Yes, I do.。
小题4:根据Because可知，上句问的是原因。故填Why。
小题5:根据once a week“一周一次”可知，问的是多久上一次绘画课。故填How often do you have an art lesson?。