1. [单选题]活塞销磨损程度可用其_______表示
A. 圆度误差
B. 圆柱度误差
C. 几何形状误差
D. 磨损量
2. [单选题]Which of the following problems should be taken when cleaning the air filter on a diesel engine equipped with a turbocharger? .
A. Reduce engine speed to idle before removing the filter
B. Soak the dirty filter in kerosene only
C. Blow out the air inlet with compressed air
D. Cover the air inlet after removing the filter
