单项选择题
A.the expansion tank is lack of water
B.the expansion tank is over flowing
C.there is something wrong with the cooling system
D.there is something wrong with the engine
单项选择题 As an alternative to the conventional seawater cooling system, is based on principles about cooler locations, （）flow control and preheating, but with a central cooler and one additional set of pumps（）.
单项选择题 （）is harmful for fuel pumps, fuel valves, cylinder liner, exhaust valve seats, and the turbocharger blades as well.
单项选择题 The booster pump, which supplies diesel oil to（） , should have a possibility of being powered by compressed air or by emergency power.