二级灵敏度的火灾探测器用于()。
A.吸烟室
B.一般用户
C.宿舍
D.办公室
参考答案：B, C, D
— Roderick had an accident yesterday.
— How come ?He very carefully. [ ]
A. drove
B. drives
C. had driven
D. has driven
传统生活方式以住窑洞、吃面食为主的居民，主要分布在[ ]
A．北方地区
B．南方地区
C．西北地区
D．青藏地区
