题干
—What will the phone ?
—The same as you said, eight hundred dollars each.
A：spend
B：cost
C：pay
D：afford
答案(点此获取答案解析）
B
—What will the phone ?
—The same as you said, eight hundred dollars each.
A：spend
B：cost
C：pay
D：afford
的图象过点
，如果点
在函数
的前
项和为 （ ）