2016年上半年,无可替代的心脏病廉价救命药“鱼精蛋白”再次出现全国性缺货,部分网民主张对其适当涨价以解决缺货问题。设P为价格,Q为数量,下列能解释网民这一主张的图示是( )
Clerk: ____ I help you?
Mary: Yes, please. I want a sweater.
Clerk: What ____ do you want?
Mary: Blue.
Clerk: Here you are.
Mary: How ____ is it?
Clerk: Nine dollars.
Mary: I'll ____ it. Thanks.
Clerk: You're ____.