A wooden plug fitted tightly in the vent of a damaged tank may prevent the tank from（）.

A.equally sharing the load
B.jammed together
C.as far apart as possible
D.rove to the highest mechanical advantage

A.generally shorter than the others and is used to steer with
B.is longer than the others and is used as the stroke oar
C.is raised in the bow of the boat for the steersman to steer by
D.longer than the others used for steering

A.a short length of line used for temporarily holding another line
B.a snatch block for handling a topping lift
C.an engine order telegraph
D.the brake on a cargo winch