题干
-- Do you still remember when you first met John?
--- I can’t quite remember, but I’m sure it was ______ Friday afternoon because we were at ______ school for a meeting.
A：/; the
B：the; /
C：a; /
D：/;a
答案(点此获取答案解析）
C
n(n∈N*)的展开式中，前三项系数成等差数列，则展开式中的常数项是 ( )．