一般来说，布局城市的理想环境是：[ ]
A．山区河谷地带
B．平原地形
C．高原地形
D．丘陵地形
答案：B
------Have you known each other for long?
------ Not very, ________we started to work in the ABC Motor Company.
A．before
B．since
C．when
D．after
请说出中国的十二生肖？
