单项选择题
During operation, the （）should check the working condition of the derrick.
A.foreman B.operator C.opener D.stevedore
单项选择题 （）has more than ten percent broken wires. Stop using it at once.
单项选择题 It is flammable cargo. Keep it away from the （）.
单项选择题 （）must be kept away from dry cargo.
