A: (1)_____________________________? B: Yes, please. I want a sweater for my daughter. A: Look! Here are some sweaters for girls. (2)_____________________________? B: Size M. A: Do you like this red one? B: Yes. My daughter likes red best. (3)________________________? A: $25. B: (4)________________________. Do you have any cheaper ones? A: How about this one? It's only$18. B: Ok, I'll take it. Here's the money. (5)________________________. A: You're welcome.
平行的直线方程是（）。
