单选题 The fuel injection system is very important, so any trouble of it will____the operation of the main engine(　　).

单选题 When we arrived here yesterday,their ship_____for three days(　　).

单选题 The poor quality of the fuel has_____ with the breakdown of the engine,I'm afrid(　　).

单选题 I'm not good at English and I can't read the instruction book for the main engine____the help of the dictionary(　　).

单选题 This brand of switch costs____that brand(　　).

单选题 It is such a moder ship____the engineers and motormen don't have to stay in the engine room all the time(　　).

单选题 You can never start the engine____you have found and removed the trouble(　　).

单选题 The chief engineer_____on board the ship for five years by the end of this year(　　).