题干

 据2015年央视“3•15”晚会曝光,山东省一些地区非法生产的调和汽油中含有甲缩醛(C3H8O2),对汽车油路有破坏作用.下列说法不正确的是(  )

A:甲缩醛属于有机物

B:甲缩醛中碳、氢、氧元素的质量比为3:8:2

C:甲缩醛的相对分子质量为76

D:甲缩醛中碳元素的质量分数约为47.4%

上一题 下一题 0.0难度 选择题 更新时间:2016-01-22 03:31:09

答案(点此获取答案解析)

B

同类题2

阅读下面短文,从短文后各题所给的四个选项(A、B、C和D)中,选出可以填入空白处的最佳选项。

    As the saying goes, rose given, fragrance in hand. I am always in the 1 of giving money to every beggar or homeless person I pass by. My friends say it is not good to 2. We may come across beggars or homeless people begging every day and all beggars have their ability to survive. It 3 them that I never listen.

    On a 4 day, my friend and I were walking to the 5 when I passed a beggar lady. I had seen her several times before and had always given her a few 6. That day, I gave her 2 Euros. I was waiting for the bus and reading a book when I7 to see that lady standing in front of me. She 8 me a piece of paper covered in a plastic bag to prevent it from getting 9. She stood there, looking at me 10. Putting away my book, I took the paper, which 11 she and her family had to 12 their country because of floods, and she was 13 to support them. She had got a bit of money, but she needed 5 14 Euros to get home. I 15 in my pockets and found 20 cents. My friend 16 a 5 Euro note. I asked her to give it to the lady, and said that I would 17 the next day. When she got the money, the lady hugged us and said thanks again and again, and went on her way. Later on the bus, I wondered where her home was and 18 she had gotten to this country. In her story, I felt that my friend and I would always remain part of it as the 19, who helped her get home on a rainy day. But for me, helping a stranger did bring me happiness, giving me a pleasant 20.