单项选择题 In the emergency alarm signals, if the alarm or whistle two long sounds followed by one short sound for 1 minute, it is the （） emergency.

单项选择题 In the voyage, when carrying out abandon ship drill （） should be test every time.

单项选择题 According to the ship emergency plan, when average accident happened and the captain made the decision to withdraw from the engine room before leaving the engine room, the wrong operation is that （）