A vessel is constructed with a steel hull and an aluminum superstructure. Which statement is TRUE?()
A、The aluminum will provide greater resistance to the spread of fire by conduction
B、The aluminum structure is usually attached to a steel coaming by a method that insulates the two metals
C、If the superstructure is stressed,an aluminum structure requires additional expansion joints to prevent fracture
D、The steel at the area of the aluminum-to-steel connection must be closely checked for galvanic corrosion