题干

下列有关生物体内水和无机盐的叙述错误的是(  )

A:细胞代谢过程中,叶绿体、核糖体和中心体中都有水生成

B:水既是细胞内良好的溶剂,又是生物体内物质运输的主要介质

C:无机盐离子对维持血浆的渗透压和酸碱平衡等有重要作用

D:镁是构成叶绿素的必需成分,植物缺乏镁会导致叶片发黄

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A

同类题4

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Tom and Steve were twin brothers. Tom loved to play basketball. But Steve loved to read books. One day Tom was playing basketball 21  he fell and broke his leg. When they took him to the hospital, the doctor said he wouldn’t be able to play for six months. Steve went 22  him to and brought him books on basketball. At first Tom wasn’t going to read them. Then he began to read them and 23 that there were ways he could play basketball better. He began to think that books weren’t 24  .

   When Tom’s leg started getting better, Steve would help him by going for walks with him.  25 Tom’s doctor said he could start playing basketball again. Then Tom showed Steve how to toss(投)for baskets. Steve found that he enjoyed it.

   Then Tom was ready to 26  the basketball games. Steve went to watch the games and enjoyed himself. They then  27 practiced basketball and read books together.

   So you can see, when  28  happens, something good may also happen. Steve showed Tom about books and Tom showed Steve about basketball.

So you can also  29 showing others something that you like to do and they can show you something that they like to do. 30 you can find new things to do.

21A. until              B. when            C. after           D. where

22A. on seeing          B. to call            C. to visit         D.to look

23A. saw              B. looked            C. read           D. found

24A. good             B. bad              C. better           D. worse

25A. But              B. However          C. Finally         D. So

26A. take              B. win              C. lose            D. join in

27A. always            B. never            C. seldom          D. much

28A. anything good      B. something nice     C. something bad   D. anything wrong

29A. try               B. practice           C. enjoy          D. like

30A . On the way       B. By the way        C. In a way       D. In this way