单项选择题
The officer in charge of the engineering watch shall continue to be responsible for machinery operations, （）the presence of the chief engineer in the machinery space.
A.as long as B.unless C.despite D.till
单项选择题 We have stayed at Shanghai port for a long timeThe fouling on the ship’s hull greatly increases her （）.
单项选择题 We’d better （）economic speed （）fuel consumption.
单项选择题 This machine （）out of order very often, but now it works well.
