Frapping lines（）.

A.secure the lifeboat in the davits when in the stowed position

B.bring the lifeboat close alongside the rail in the embarkation position

C.give the occupants a safety line when the boat is being lowered from the embarkation level

D.reduce the swinging of the lifeboat at the embarkation level

要上胶订的书帖，最好用捆书板捆扎。