1990～1995年中我国城市共增加多少个？（）
A．418
B．672
C．190
D．254
参考答案：D
已知数列{an}的通项公式为an=-2n+11，其前n项的和为Sn（n∈N*），则当Sn取最大值时，n=______．
29. We stayed in a quiet hotel, ________________.
A．next to it was a thick woods
B．next to which was a thick woods
C．next to it there was a thick woods
D．next to which a thick woods was
