题目

The Art of Travel Photography Course on DVD $ 99.95  $ 29.95 Most of us wouldn't dream of travelling without bringing a camera along. Photographs not only let us share our experiences with others，but they preserve once-in-a-lifetime moments precisely the way we want to remember them. Yet all too often, we find that our photos fall short of our expectations. And our dull results are made all the more disappointing by the knowledge that we may never return to the pictured locale* We've all learned how difficult it can be Co capture (捕捉）the magic of the moment. But by understandia g下列物质在氧气中充分燃烧后的气体（1．01×105 Pa，120℃），通过足量的过氧化钠充分反应后，过氧化钠增重b g，符合b>a 的选项有                                            （    ）       A．HCHO                                          B．CH3COOCH2CH3       C．HOOCCOOH                                   D．HCOOH