单项选择题
A.They are self-priming B.Decreasing the speed of rotation will decrease the discharge pressure C.Opening the discharge valve wider will increase the discharge pressure D.All of the above
We’ve changed our（）not to start loading this evening．A....
单项选择题We’ve changed our（）not to start loading this evening．
A.heart B.hearts C.mind D.minds
We’ll put off（）until Friday．A.to dischargeB.dischargeC....
单项选择题We’ll put off（）until Friday．
A.to discharge B.discharge C.discharging D.to be discharging
We have finished（）and are ready for sailing．A.loadB.loa...
单项选择题We have finished（）and are ready for sailing．
A.load B.loading C.will load D.to load
