问题 选择题

如图为含有同一种元素的a、b、c、d、e五种物质的转化关系.其中a是单质,b是气态氢化物,c、d是氧化物,e是该元素最高价氧化物对应的水化物,则a可能是

①C ②N2 ③S ④F2中的

[ ]

A.只有①和③  

B.只有④

C.①②③  

D.①②③④

答案

答案:C

问答题

       19世纪中期到20世纪初期,面对日益严重的民族危机,中国社会各阶层积极探寻救国良策。

请问:该时期中国的地主阶级洋务派、资产阶级改良派、资产阶级革命派分别提出了什么救国方案?各是怎样实践的?从实践的最后结果你能得出什么认识? 

                                                                                                                                                              

                                                                                                                                                              

                                                                                                                                                              

                                                                                                                                                              

                                                                                                                                                              

                                                                                                                                                              

                                                                                                                                                             

单项选择题