汽车罐车加油车油泵能满足吸注等作业功能，油泵吸油深度应（）。
A.不小于4m
B.不大于4m
C.等于4m
D.不小于3m
参考答案：A
---Where did you get to know her?
---It was on the farm we both once worked in the 1970s.
A．that
B．which
C．when
D．where
绝缘子做成波纹形是为了（）
A、增强机械强度
B、美观
C、增加爬弧距离
D、保证耐压强度
