单项选择题
A ground in an electrical circuit outside the engine room （）.
A.cannot be detected tinder normal conditions B.is of no consequence to engineering personnel C.is indicated at the branch circuit breaker panel D.is indicated by the ground detecting lamps on the main switchboard
单项选择题 Grease coatings on electrical contact surfaces increase contact resistance and should be removed with a/an （）.
单项选择题 Aboard ship, a grounded field coil in an AC motor can be determined by using a （）.
单项选择题 A generator is prevented from becoming motorized by the use of a/an （）.
