问题
多项选择题
以下哪些描述与维生素C相符( )。
A．结构中含内酯结构，为L(+)-苏阿糖型
B．水溶液pH值大约8.2
C．水溶液可发生酮式-烯醇式互变
D．水溶液易被空气氧化
E．临床用于防治坏血病，预防冠心病
答案
参考答案：A,C,D,E
解析：［知识点］ 水溶性维生素
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以下哪些描述与维生素C相符( )。
A．结构中含内酯结构，为L(+)-苏阿糖型
B．水溶液pH值大约8.2
C．水溶液可发生酮式-烯醇式互变
D．水溶液易被空气氧化
E．临床用于防治坏血病，预防冠心病
参考答案：A,C,D,E
解析：［知识点］ 水溶性维生素
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| Summer holidays came.Little Thomas was very 1 .His father said he was going to 2 him and his sister and his mother to China.The boy had been to many 3 and taken photos there.He often 4 them to his friends.But he saw the Great Wall,the Palace Museum and Summer Palace only on 5 . So he borrowed some geography books.He tried to find China's Beijing and Shanghai in the 6 .He studied carefully what foods were 7 in those cities.He hoped to have a good time there. The boy 8 much time on that and couldn't listen to his teachers carefully in classes. Sometimes he 9 he was travelling in Beijing.He had no time to go over his lessons.So he fell 10 others and failed in the exams.Mrs Smith who taugh him maths called him in her 11 and told him to be a good student.He promised(许诺),but soon he 12 it.The woman had to tell his mother about it on the telephone this morning. "Aren't you 13 of yourself,Thomas?You're the worst pupil in your 14 ."said the mother. "What does it have to do with me?The worst one was yesterday transferred(转学)to 15 school."he answered. | |||
| ( )1. A. sad ( )2. A. carry ( )3. A. villages ( )4. A. sent ( )5. A. pictures ( )6. A. TV ( )7. A. color ( )8. A. spent ( )9. A. went ( )10. A. behind ( )11. A. bedroom ( )12. A. copied ( )13. A. glad ( )14. A. class ( )15. A. a better | B. sorry B. take B. mountains B. showed B. maps B. maps B. expensive B. paid B. stopped B. off B. office B. found B. interested B. family B. the other | C. happy C. send C. forests C. told C. photos C.VCD C. cheap C. saved C. dreamed C. over C. kitchen C .remembered C. shy C. team C. another | D. worried D. drive D. countries D. gave D. stamps D. radio D. delicious D. waited D. continued D. around D. library D. forgot D. afraid D. row D. a higher |