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(16分)人工合成的生长素类似物,如2.4—D、萘乙酸等,具有与生长素相似的生理效应。它们在生产上的应用很广泛。
(1)2,4—D 是一种最早应用的选择性除草剂,在农业生产上常用它除去单子叶农作物田间的双子叶杂草。单子叶农作物与双子叶杂草对2,4—D浓度的反应如右图曲线所示。

①从图中可以看出2.4—D作用的特点是_______________。
②图中X点(甲、乙的交点)对应的浓度对于双子叶杂草的作用效果是______________,2.4—D作为除草剂的最佳使用浓度是_______________点所对应的浓度。
③近几年,媒体经常报道有些农民使用除草剂导致作物绝产的消息。如是某农民使用的2。4—D不是假冒产品,请你分析导致作物绝产的最可能原因是__________________
(2)2.4—D还能促进插条生根。为了探索2.4—D促进插条生根的最适浓度,某生物兴趣小组先做了一组梯度比较大的预实验,实验的结果如下图所示。
①图中纵坐标的标识是______________;推测最适浓度的大致范围在______________之间。
②做预实验的目的是__________________   正式实验中要实现实验目的,最少需要设置___________组实验(相对浓度梯度为1)。

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Most adults(成年人)once studied at school, had classes and did their homework every day. The same? ? ? is going on at school now. ??? ? it seems that doing weekend homework is ? ? problem for the modern students.

??? All the students should agree that weekend homework should be abolished(取消).It's??? ? for them studying at school five days a week. They have a lot of interests. With homework to do on Saturday and Sunday, when can they find?? ?? to help around the house, go and see a football or basketball game or a good film, join in family recreations(娱乐),or just have??? ? at home? Because of these other activities, the homework can't be finished until????? .So their weekend homework is usually done in such a hurry that on Monday teachers are????? and often threaten (威胁)to fail(使考试不及格)whole class of students because they know nothing about the??? . If there is no weekend homework for the students to do, they will be happy to go to school on Monday? ? having a good rest and to learn what the teachers teach.

1.A. thing??? ????????????? B. school ????????????? C. class??? ????????????? D. homework

2.A. Also??? ? ????????????? B. But??? ????????????? C. Still?? ????????????? D. Though

3.A. no??? ????????????? ????????????? B. another? ????????????? C. one??? ????????????? D. other

4.A. not enough????????????? B. enough? ????????????? C. no good? ????????????? D. no use

5.A. friends??? ????????????? B. time??? ????????????? C. places??? ????????????? D. money

6.A. a rest??? ????????????? B. an exam ????????????? C. a lesson?? ????????????? D. a picnic

7.A. Monday afternoon??? ????????????? ????????????? B. Saturday afternoon?

C. Friday night??? ????????????? ????????????? ????????????? D. Sunday night

8.A. pleased??? ????????????? B. sorry??? ????????????? C. unhappy?? D. not worried

9.A. lesson??? ????????????? B. games??? ????????????? C. interests? ????????????? D. activities

10.A. until??? ????????????? B. when??? ????????????? C. before?? ????????????? D. after

 

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Most adults(成年人)once studied at school, had classes and did their homework every day. The same     is going on at school now.       it seems that doing weekend homework is      problem for the modern students.

    All the students should agree that weekend homework should be abolished(取消).It's     for them studying at school five days a week. They have a lot of interests. With homework to do on Saturday and Sunday, when can they find       to help around the house, go and see a football or basketball game or a good film, join in family recreations(娱乐),or just have     at home? Because of these other activities, the homework can't be finished until      .So their weekend homework is usually done in such a hurry that on Monday teachers are      and often threaten(威胁)to fail(使考试不及格)whole class of students because they know nothing about the     . If there is no weekend homework for the students to do, they will be happy to go to school on Monday      having a good rest and to learn what the teachers teach.

1.A. thing             B. school                 C. class                 D. homework

2.A. Also                  B. But                     C. Still           D. Though

3.A. no                           B. another          C. one                 D. other

4.A. not enough               B. enough          C. no good               D. no use

5.A. friends                   B. time                      C. places       D. money

6.A. a rest            B. an exam          C. a lesson       D. a picnic

7.A. Monday afternoon   B. Saturday afternoon

C. Friday night    D. Sunday night

8.A. pleased                 B. sorry             C. unhappy       D. not worried

9.A. lesson          B. games           C. interests       D. activities

10.A. until            B. when            C. before         D. after

 

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Most adults(成年人)once studied at school, had classes and did their homework every day. The same    is going on at school now.      it seems that doing weekend homework is      problem for the modern students.
All the students should agree that weekend homework should be abolished(取消).It's    for them studying at school five days a week. They have a lot of interests. With homework to do on Saturday and Sunday, when can they find      to help around the house, go and see a football or basketball game or a good film, join in family recreations(娱乐),or just have    at home? Because of these other activities, the homework can't be finished until     .So their weekend homework is usually done in such a hurry that on Monday teachers are     and often threaten(威胁)to fail(使考试不及格)whole class of students because they know nothing about the    . If there is no weekend homework for the students to do, they will be happy to go to school on Monday     having a good rest and to learn what the teachers teach.
小题1:
A.thingB.school C.classD.homework
小题2:
A.AlsoB.ButC.StillD.Though
小题3:
A.noB.another C.oneD.other
小题4:
A.not enoughB.enoughC.no goodD.no use
小题5:
A.friendsB.timeC.placesD.money
小题6:
A.a restB.an exam C.a lessonD.a picnic
小题7:
A.Monday afternoonB.Saturday afternoon
C.Friday nightD.Sunday night
小题8:
A.pleasedB.sorryC.unhappyD.not worried
小题9:
A.lessonB.gamesC.interestsD.activities
小题10:
A.untilB.whenC.beforeD.after

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完成句子
【小题1】我的电脑出毛病了,需要修理一下。
Something has __________________________________  my computer, it needs repairing.
【小题2】玩太多的电脑游戏对青少年有不好的影响。
Playing too many computer games ___________________________________ teenagers.
【小题3】众所周知, 勤奋工作导致了他的成功。
It is known to all that _____________________________________ his success.
【小题4】医生说他正与疾病做顽强斗争。
The doctor said he ________________________________________ the disease.
【小题5】当我到达电影院时,电影已经开始一刻钟了。
When I got to the cinema, the film __________________________________________________.
【小题6】他的房间太乱,没有人想进出。
His room is _____________________________________ that nobody wants to enter it.

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