单项选择题
A.working at intervals and properly heating
B.warming up to 70℃, increase water supply flow
C.improving impulse of water supply
D.reducing water supply flow
单项选择题 If separating effect is not good, we can improve it by （）
单项选择题 If found oil when we open low oil level plug of separator, it indicates （）
单项选择题 After stopping oily water separator, sea water should be permitted for （） minutes,（）should be closed after stopping pump to reduce oxidation corrosion of inner wall.