题干
―Where is the bank, please?
―It is ____ the post office and the library.
―It is ____ the post office and the library.
A：next
B：at
C：betwee
D：i
答案(点此获取答案解析）
C
＝a0＋a1x＋a2x2＋…＋a10x10＋
，则a9＝