The carbon deposits on the piston crown and in the ring grooves （）.

[单选题]Carbon is an element， while carbon dioxide is a( )A.materialB.substanceC.or

[单选题]Carbon is( )， while carbon dioxide is a compound.A.a materialB.a substanceC

[单选题](piston area)×(piston stroke)×(numbers of the cylinders)=engine( ).A．brake horsepowerB．displacementC．cylinder volumeD．cylinder clearance

[单选题]One of the disadvantages of using carbon dioxide to extinguish a fire in an enclosed space isA．the 'snow' which is sometimes discharged along with the gas is toxicB．prolonged exposure to high concentrations of CO2 gas causes suffocationC．rapid diss

[单选题]Their signing of the treaty was regarded as a conspiracy against the Britis

[单选题]In order to cut down on the carbon emission，more people choose to travel______.A．by electric car，bicycle or planeB．by private car，bicycle or busC．by bus，electric car or planeD．by bicycle. bus or electric car

[单选题]Portable carbon dioxide fire extinguishers should be sent ashore to be rechargedA．when the remaining charge volume is less than 90 percent of the required volumeB．at each inspection for certificationC．at each annual inspectionD．when the weight loss e

[单选题]As compared to carbon dioxide，dry chemical has which advantage?（）A . CleanerB . Effective on metal firesC . Greater rangeD . More cooling effect

[名词解释] 异头碳（anomeric carbon）

[单选题]车型crown的中文名称是（）A . 威飒B . 皇冠C . 逸致D . 卡罗拉