题干
— Do you know the new mobile phone yesterday?
—Maybe about 2, 800 yuan. I'm not sure.
A：how much she paid for
B：how much will she pay for
C：how much did she pay for
D：how much she will pay for
答案(点此获取答案解析）
A
为等差数列，公差 
（ 
），且
）