淋水系统的校准周期应不大于（）个月.
A、3
B、6
C、12
D、24
参考答案：B
This job is really tiring. I should ________ a new job. [ ]
A. to consider to find
B. to consider finding
C. consider finding
D. consider to find
与呼吸系统疾病关系最密切的是（）
A.吸烟
B.酗酒
C.吸毒
D.不洁性行为
E.工作紧张
