The valve on the discharge side of a cargo pump on a tanker will usually be a（）.

A.before the gripes are removed
B.before loading the passengers
C.after loading the passengers
D.after the boat is afloat

A.does not exceed
B.should exceed
C.should be up to
D.should be no more than

A.environmental loading
B.variable loading
C.fixed loading
D.basic loading