题目

鉴别H2、CO及CH4常采用的方法是（     ） A．根据燃烧产物的不同                    B．根据燃烧时火焰的不同 C．根据是否能发生爆炸                 D．根据密度大小 答案：AHe was not able to catch the early bus and ________ he was late for the meeting.A.as a resultB.on the other handC.on the contraryD.as to say