题干
My parents are very strict ________ me ________ my lessons.
A：at; in
B：in; with
C：with; in
D：in; at
答案(点此获取答案解析）
C
My parents are very strict ________ me ________ my lessons.
A：at; in
B：in; with
C：with; in
D：in; at
的前n项和为
，已知
，
,则
（ ）