When loading or discharging dry mud or cement，crew members should use goggles and（）.

A.a sponge used to mop up and store condensation must be kept salt free
B.only condensation on the bottom of the canopy should be collected
C.it should be strained through a finely woven cloth
D.chlorine tablets should be used to make it drinkable

A.carbon dioxide
B.dry chemical
C.foam (stored-pressure type)
D.water (cartridge-operated)