Before entering the chain locker，you should（）.

A.have someone standing by

B.make sure there is sufficient air within the locker

C.de-energize the windlass

D.All of the above

下列属于火成岩成因的岩石是（）

A.岩浆岩

B.沉积岩

C.变质岩

D.花岗岩