40. There is much scale in the jacket water cooler for main engine.

A、
A、Muchscaleisfoundinthejacketwatercoolerforauxiliaryengine.;
B、
B、Notmuchscaleisfoundinthejacketwatercoolerformainengine.;
C、
C、Alotofscaleisfoundinthejacketwatercoolerformainengine.;
D、
D、Wefindchokedinthejacketwatercoolerforauxiliaryengine.