Carbon is an element， while carbon dioxide is a( )

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

[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

The result would be higher emissions of carbon dioxide and other greenhouse gase

The result would be higher emissions of carbon dioxide and other greenhouse gase

Trees 12 _ carbon dioxide from the air . Recycle Recycle cans bottles plastic ba

如果执行检索式carbon-emission,可以同时检索出包含词组“carbon emission”和“carbon emissions”的文献信息 如果执

[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]The carbon deposits on the piston crown and in the ring grooves （）.A . should be scrapedB . should be derustedC . should be drilled outD . to be brushed off

[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