某物质在氧气中燃烧,生成二氧化碳和水的质量比是22比9,则该物质化学式可能是A.CO B CH3OH C C2H2 D C2H4Since computers arrived,my job （ ）much easier.A became B has becomeFor further details about our new products,（
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某物质在氧气中燃烧,生成二氧化碳和水的质量比是22比9,则该物质化学式可能是A.CO B CH3OH C C2H2 D C2H4Since computers arrived,my job （ ）much easier.A became B has becomeFor further details about our new products,（
某物质在氧气中燃烧,生成二氧化碳和水的质量比是22比9,则该物质化学式可能是
A.CO B CH3OH C C2H2 D C2H4
Since computers arrived,my job （ ）much easier.
A became B has become
For further details about our new products,（ ）our company's website.
A visiting B to visit
How would you like your coffee?
A Black,please.B Very much C It tastes good D No thanks
某物质在氧气中燃烧,生成二氧化碳和水的质量比是22比9,则该物质化学式可能是A.CO B CH3OH C C2H2 D C2H4Since computers arrived,my job （ ）much easier.A became B has becomeFor further details about our new products,（
化学题：选D：将比例换算成物质的量比：为CO2：H2O为0.5:0.5,则该物质的分子中,C：H=1:2,D项符合题意
英语1：选B,since引导的时间状语从句中,往往用完成时
2：无选项,你的题错了,前半句和后半句都不完整
3：A.注意how,“你要什么样的咖啡”“纯的,不要牛奶”
二氧化碳和水的质量比是22比9，即某物质的C和H比例为1：2，所以选D 过去完成时选B 固定形式选A 固定回答选C