题干
— When did you arrive at school this morning?
—At 7:30 o' clock.
A：leave
B：reach
C：visit
答案(点此获取答案解析）
B
— When did you arrive at school this morning?
—At 7:30 o' clock.
A：leave
B：reach
C：visit
为等差数列，公差 
（ 
），且
）