单项选择题
A.in which B.by which C.through which D.from which
The main engine is cooled with fresh water （）is added s...
单项选择题The main engine is cooled with fresh water （）is added suitable small quantities of chemicals to prevent corrosion.
A.in which B.on which C.to which D.by which
（）during the last repair?A.Did you have No.4 cylinder r...
单项选择题（）during the last repair?
A.Did you have No.4 cylinder repair B.Do you have No.4 cylinder repaired C.Didn’t you have No.4 cylinder repairing D.Didn’t you have No.4 cylinder repaired
Hardly had the engine started （） the temperature of the...
单项选择题Hardly had the engine started （） the temperature of the cooling water suddenly rose up to 40℃.
A.then B.than C.when D.after
