单项选择题 During the running of the diesel engine, if the supply of cooling water is interrupted or the temperature of cooling water out of the cylinder is too high, the duty engineer should （）

单项选择题 If the main engine starting consecutively failed （） times, it should be found the cause before another starting.

单项选择题 Before engaging the turning gear and turning the diesel engine, which of the following operation should be done except （）