有研究者提出：叶绿素的合成既与外界条件有关，又与植物自身有关。为检验这一假设，有人利

发布时间：2021-01-15 22:16 │ 来源：www.tikuol.com

题型：单项选择题

问题：

有研究者提出：叶绿素的合成既与外界条件有关，又与植物自身有关。为检验这一假设，有人利用豌豆苗做了如下实验：将剪去两片子叶的豌豆幼苗分成四组，在不同条件下培养，实验方法及结果见表。

但这个实验不能证明子叶在叶绿素的合成过程中有何作用。为此，需补充设计一组新的实验。你认为应如何设置（）

①．实验材料取完整幼苗；培养液用蒸馏水：光、温控制为：光照，25℃。

②．实验材料取完整幼苗；培养液用缺镁培养液：光、温控制为：光照，25℃。

③．实验材料取完整幼苗：培养液用缺镁培养液：光、温控制为：黑暗，10℃。

④．实验材料取完整幼苗；培养液用蒸馏水；光、温控制为：黑暗，10℃。

A.①或②

B.②或③

C.①或③

D.②或④

考点：自然科学知识竞赛生物知识竞赛(综合练习)生物知识竞赛(综合练习)题库

题型：单项选择题

“横看成岭侧成蜂，远近高低各不同，不识庐山真面目，只缘身在此山中。”这首诗说明的哲学道理是

A．人们永远不可能认识事物的真相 D．认识受时间、地点和条件的制约

C．现象和本质相互联系、不可分割 D．假象不是事物本质的表现

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我国降水空间分布特点是（　　）

A．从东北地区向西南地区递减

B．从东南沿海向西北内陆递减

C．夏季降水多，冬季降水少

D．从南部高原向北部平原递减

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题型：单项选择题

完形填空。
阅读下面短文，从短文后所给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。

     Paul Carson, a music teacher, was driving along a country road with his sister Nora.   1   he saw a
man in a big American car who _2  the man wanted by the police.  3  by a reward (奖赏) of fifty pounds,
the sister and brother _4  to catch the criminal(罪犯) by following him  5  .  As soon as the man entered
Seldon Manor, a _6  belonging to Paul's friend Mr. Lightfoot, Paul shut him in and then drove to   7  .
Realizing that Paul had made a _8  because the criminal had been put into prison that morning , the police
officer set off immediately with Paul to set the man free. The man who was _9 up in the house was really
an American visitor from    10 City. Paul and Nora felt very much    11    for what they had done. This
  12  action of theirs would surely make them the laughing-stock of the whole town. But a letter from the
American   13  changed the situation. _14  blaming(责怪) him, the American visitor thanked Paul for
shutting him up in his
  15  house. It 16 that Seldon Manor was the American ancestors' home. He had come  17 to England
to look for it. In order to show his 18 , he offered the sister and brother a check 19 fifty pounds. Paul
and Nora got the 20  in the end, though in a quite different way.

(     )1. A. Clearly
(     )2. A. looked like
(     )3. A. Feared
(     )4. A. wondered
(     )5. A. closely
(     )6. A. factory
(     )7. A. the railway station
(     )8. A. mistake
(     )9. A. pulled
(     )10. A. London
(     )11. A. joyful
(     )12. A. rude
(     )13. A. president
(     )14. A. Instead of
(     )15. A. small
(     )16. A. turned out
(     )17. A. all the time
(     )18. A. anger
(     )19. A. as
(     )20. A. honor

B. Finally
B. cared about
B. Attracted
B. promised
B. anxiously
B. garden
B. the city
B. choice
B. shut
B. New York
B. ashamed
B. kind
B. couple
B. As well as
B. own
B. turned up
B. all the way
B. thanks
B. to
B. gift

C. Quickly
C. hunted for
C. Moved
C. decided
C. separately
C. farm
C. his home
C. joke
C. brought
C. Paris
C. pleased
C. worthy
C. visitor
C. In case of
C. new
C. turned on
C. all the same
C. pity
C. for
C. position

D. Suddenly
D. called on
D. Shared
D. struggled
D. excitedly
D. house
D. the police station
D. adventure
D. sent
D. Cairo
D. disappointed
D. clever
D. policeman
D. As a result of
D. big
D. turned down
D. by chance
D. interest
D. of
D. reward

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题型：单项选择题

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私学是孔子首创的，这也是孔子对中国传统教育的杰出贡献之一。

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题型：单项选择题

若实行海水淡化供应饮用水，下列方法在原理上完全不可行的是( )

A．用明矾使海水中的盐分沉淀而淡化

B．利用太阳能使海水蒸馏而淡化

C．将海水缓慢凝固以获取淡化的饮用水

D．将海水通过离子交换树脂，以除去所含盐分的离子

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