题干

维生素C(C6H8O6)主要存在于蔬菜、水果中,它能促进人体生长发育,增强人体对疾病的抵抗力.下列关于维生素C的说法中正确的是(   )

A:维生素C是氧化物

B:维生素C中含有3种元素

C:维生素C中含有20个原子

D:维生素C中碳的质量分数为 620 ×100%

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答案(点此获取答案解析)

B

同类题5

读下面短文,按照句子的语法情况和上下文连贯的要求,在空白处填入适当的词或用括号中所给词的正确形式填空。每空不超过两词。

    Florence Nightingale was a nurse who saved many people in the 19th cenury. She was named after the city of Florence in Italy.

    Florence was ____ unusual young woman for her time, bemuse she didn't want to go to parties and get married. She wanted to be a nurse and help people. Her family ____ (not)want her to become a nurse because hospitals back then were dirty, horrible places.

    ____ the age of thirty-one, Florence went to Germany and learned all about nursing. It was hard work, ____ she loved it.

    In 1854, lots of British soldiers went to fight in the Crimean War. Army hospitals were filled with injured people, but there ____ (be)no nurses and many soldiers died. Florence and a team of nurses went to help.

    Florence worked 20 hours a day to make the hospital ____(clean)and safer place. She brought fresh food, she cleaned the beds and she used clean bandages on the wounded soldiers fewer ____ (man) were dying.

    At night, Florence talked to the injured soldiers and helped them ____(write) letters to their families. They called her "the lady with the lamp", ____ she always carried a lamp.

    When Florence returned to England, people called her a hero. Queen Victoria wrote her a letter to say thanks, She ____ (give)the honor(荣誉)----Order of Merit, becoming the first woman to receive it