A、B、C、X均为中学化学常见物质，一定条件下它们有如图转化关系(其他产物已略去)，下列说法正确的是( )
A．若X为Fe，则C可能为Fe(NO3)2
B．若X为KOH溶液，则A可能为Al
C．若A、B、C均为焰色反应呈黄色的化合物，则X一定为CO2
D．若X为O2，则A可为有机物乙醇，也可为非金属单质硫
答案：A
A项，若X为Fe，A为HNO3，则B为Fe(NO3)3，C为Fe(NO3)2；B项，若X为KOH溶液，A为Al，则B为KAlO2，但B不能与X反应转化为C；C项，若A、B、C为钠的化合物，X为SO2时也符合转化关系；D项，若X为O2，则A可为有机物乙醇，但不能为单质硫，单质硫与氧气反应不能生成三氧化硫。
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| When I was young, my father told me that little acts of kindness may give one great happiness. Since then I have always tried to help people in 1 . One hot summer afternoon, I was 2 down the highway to New York when another car suddenly 3 into my lane (车道). My car was in the far right lane,so it ran onto the roadside. As a(n) 4 driver,I moved my car quickly and skillfully back onto the highway without causing any accident. I was 5 with that driver,but I thought that he just did not pay attention to the lane change, and he 6 did not do that on purpose (故意).The car ran away 7 after cutting me off. Very soon it disappeared from sight. After a while,I came around a curve (弯道) and found the 8 car. The driver was walking along the roadside. He was an elderly man and looked 9 . With no telephone nearby and the nearest services twenty miles away. I decided to 10 and see what the problem was. The man's car had a flat tire (瘪胎). Although he had a spare tire,he had nothing to work with. I decided to 11 him. I changed the tire for him and allowed him to sit in my Air-conditioned car while I did it. Fifteen minutes later, I 12 the work. I was hot and tired,but I really felt 13 after an act of kindness to the man who had earlier 14 my car ran off the road. You can really enjoy great 15 from kindness acts, so always lend your hands to others in trouble. | ||||
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