Please arrnge for the workers to do the（）work during loading the trucks and heavy cargo on the ship, and also supply the necessary materials for the work.

A.insure
B.ensure
C.assure
D.assume

A.ventilating the space
B.noy ventilating the space
C.proper use of paper separation and dunnage
D.segregation of cargo by using different hatches

A.valuable
B.invaluable
C.valueless
D.priceless