题目

下列物质的变化，不能通过一步化学反应完成的是（ ）A.Na2O2→Na2CO3 B.SO2→H2 SO4 C.SiO2→Na2SiO3 D.SiO2→H2SiO3 答案：【答案】D【解析】A.Na2O2→Na2CO3选择二氧化碳即可一步实现，故A不选；B.SO2→H2 SO4选择H2O2即可一步实现，故B不选；C.二氧化硅是酸性氧化物，能和强碱反应生成盐和水，SiO2→Na2SiO3选择NaOH能一步实现，故C不选；D.二氧化硅不溶于水，不能和水反应，SiO2→H2SiO3不能一步实现，SiO2必须先和强碱反应生成硅短文改错。 　　There was once a millionaire whom loved (1) ________ money than anything in the world. He didn't know (2) ________ exactly how many he had. So he took on a little (3) ________ girl to count all his money to him. (4) ________ It takes the little girl six days to count (5) ________ all the money. Then she told the millionaire that (6) ________ she had forty-two million dollars, he was wild (7) ________ for joy and asked,“How much pay do you want?” (8) ________ He thought that because she was only a child, he (9) ________ could cheat her into taking very small amount. (10) ________