High clouds，composed of small white flakes or scaly globular masses，and often banded together to form a “mackerel sky”，would be classified as（）.

A.moor a damaged barge to the bank and leave
B.remove and deliver a loaded barge from a multiple tow
C.remove a barge while locking through
D.tow an empty barge astern

A.to right the raft if it capsizes
B.to carry the raft around on deck
C.for crewmen to hang on to
D.to hang the raft for drying

A.Fires in electrical equipment
B.Flammable oils and greases
C.Class "A" fires in ordinary combustibles
D.Materials containing their own oxygen