启动螺杆泵井时，井口的清蜡阀门应处于（）状态，且两边手轮的开启圈数应基本一致。
A、关闭
B、开启
C、一侧关闭
D、一侧开启
参考答案：B
—How often ______ your school sports meeting ______?
—Once a year. [ ]
A. does, hold
B. was, held
C. is, held
D. is, taken place
应明确客户投诉和纠纷处理流程，但为了保护客户的隐私不得将其情况公示。( )
