单项选择题
A.only when the load is taken off the cable B.only when there is a load on the cable C.only when activated by the controls at the lowering station D.at any time
An “atoll cloud” forming over an island due to heating ...
单项选择题An “atoll cloud” forming over an island due to heating of the land during the daytime would be which type? （）
A.Cirrus B.Cumulus C.Stratus D.Nimbus
An “ABC” dry chemical fire extinguisher would be LEAST ...
单项选择题An “ABC” dry chemical fire extinguisher would be LEAST effective against a fire in（）.
A.a mattress B.spilled liquids such as oil or paint C.high voltage electrical gear D.a trash can
AMVER is a system which provides（）.A.satellite communic...
单项选择题AMVER is a system which provides（）.
A.satellite communications B.navigational information C.weather information D.position reporting service
