题干
完成对话。
Salesgirl: Can I help you?
Mary: Yes. I want a skirt.____?
Salesgirl: It's eighty yuan.
Mary: It's too expensive. ____?
Salesgirl: Yes, we do. This skirt is only thirty-five yuan. ____?
Mary: Medium.
Salesgirl: And ____?
Mary: Yellow color.
Salesgirl: Do you like this yellow skirt?
Mary: Yes, I like it.
答案(点此获取答案解析）
How much is it,Do you have any cheaper ones,What size do you want,what color do you want
米/秒，要使光由空气射入这种玻璃，折射光线与反射光线之间成90°角，则入射角是