What is head tank in the closed cooling water system used for?

A．for the release of air from the cooling water

B．providing expansion room for heated cooling water

C．a place for implementing water and water treatment agent

D．all of the above

[单选题]In the closed cooling system, the water （）.A . is made to circulate out of the systemB . is made to circulate within the systemC . is made circulate within the systemD . is made circulate out of the system

[单选题]Head tank should be used to remove （） from cooling water.A . scaleB . sludgeC . chemicalsD . air

[单选题]关于闭合容量(Closed Capacity)与闭合气量(Closed Volume)，哪一项是错误的()A .CC和CV值相等B .正常年轻人CV大约是肺活量的10%C .随年龄增长，CV逐渐增加D .60岁以上或45岁病人仰卧位时，CV是肺总量的40%E .气道病病人的CC/肺总量的变化早于CV/肺总量的变化

[单选题]_________ is a little oil in the tankA．ThereB．ThisC．ThoseD．These

[单选题]A level gauge for a tank is to （）.A . give the pressureB . give the contentsC . give the shape of the tankD . give the accuracy level

[单选题]As to the piston cooling, of the following, which statement is not true?（）A . Because the piston is exposed to very high temperature, it must be cooledB . The lower the piston cooling temperature is, the better it isC . Both water and lube oil can be

[单选题]The cylinders, with cooling jackets, are （） to the engine frame by eight tie rods.A . screwedB . weldedC . fastenedD . rotated

[单选题]E．ach cylinder is closed at the top by a _____, made of a special heat-resistant steel.A．cylinder linerB．coupling flangeC．cylinder coverD．piston crown

[单选题]If the coolant temperature of a closed cooling water system for a diesel enginegradually increases, the trouble usually is( ).A．a broken shaft on the freshwater pumpB．an excessive accumulation of scale in the heat exchangerC．an incorrect thermostatic

[单选题]Each cylinder is closed at the top by a （）, made of a special heat-resistant steel.A . cylinder linerB . coupling flangeC . cylinder coverD . piston crow