问题 单项选择题

碘量法测定维生素C注射液含量时,加入丙酮的目的是

A.增加反应速度

B.增加维生素C的还原性

C.避免维生素C被空气中的氧氧化

D.增加溶解度

E.消除抗氧剂的干扰

答案

参考答案:E

填空题

短文填空

     Mother used to ask me what the most important part of the body is. Through the years I would guess at the correct answer. When I was younger, I thought sound was very important to us, so I said, "My 1     , mum." She said, "No, many people are deaf. But think about it and I will ask you again."

     Since making my first attempt, I had often thought over the question. So the next time I told her, "Mum, it must be our eyes." She said, "You are learning fast, but the answer isn't correct because there are 2      

people"

     Over the years, Mother asked me a couple more times and always her answer was, "No, but you are

getting smarter, dear." Last year, my Grandpa 3      away. Everybody was heartbroken, crying. When it

was our turn to say our final good-bye to Grandpa, Mum asked me, "Do you know the most 4      I was 5      when she asked me this now. I always thought this was a game between her and me. She saw the

puzzled look on my face and told me, "This question is very important. It shows you have really lived your

life." I saw her eyes full of tears. She said, "My dear, the most important body part is your 6     ." I asked, "Is it because they hold up your head?" She replied, "7     , it is because on them a crying friend or a loved one can 8      their head. I hope you will have a shoulder to cry 9      when you need it."

     Then and there I understood the most important body part is not a selfish one. It is being sympathetic to the pain of 10     .

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