A Class A EPIRB is NOT（）.……

单项选择题A check line is（）.

A.a safety line attached to a man working over the side
B.used to measure water depth
C.used to slow the headway of a barge
D.used to measure the overhead height of a bridge

单项选择题（）is the course to reach you?

A.What
B.How
C.Which
D.When

单项选择题（）is the chain?

A.How
B.What
C.Why
D.How about