第二课时: Section A: 2a, 2b, 2c. What’s his name? His name is- What’s her name? Her name is-——青夏教育精英家教网——

摘要：第二课时: Section A: 2a, 2b, 2c. What’s his name? His name is- What’s her name? Her name is-

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（10分）植物具有向重力生长的特性，下列是研究根向重力生长机理的两个实验。
实验一：将空白琼脂和含EDTA的琼脂做成帽状，分别套在甲、乙两组玉米胚根的根冠外（示意图如下）。提示：EDTA的作用是去除与其临接部位的 Ca²⁺。

将胚根水平放置培养一定时间后，观察到甲组胚根向重力（下）生长，乙组胚根水平生长。根据上述实验结果，得出实验结论：                               。
　　实验二：水平放置的胚根弯曲向下生长，与根冠近地侧的Ca²⁺浓度明显高于远地侧有关。研究表明，根总是朝着Ca²⁺浓度高的方向弯曲生长。为验证这一结论，有人设计了下列实验方案。请根据提供的实验材料和用具，写出第二步及以后的实验步骤和实验结果，并回答问题。
（1）实验材料和用具：胚根等长的萌发玉米种子，空白琼脂帽，含EDTA的琼脂帽，上面部分含Ca²⁺的琼脂帽（水平方向），培养皿等。
（2）实验步骤：
　　第一步：取若干个培养皿，在每个培养皿中放置适量的萌发玉米种子，按实验一中乙组的方法处理胚根一定时间后，移去根冠外的琼脂帽。然后将培养皿平均分成两组，编号为 A组、B 组。
　　第二步：                                                            。
　　第三步：                                                            。
（3）实验结果：                                                         。
（4）科学家进一步证实，根冠中生长素的分布受Ca²⁺浓度影响，当胚根水平放置时，重力诱导Ca²⁺向根冠下侧移动，导致近地侧的生长素浓度比远地侧高。请分析胚根的生长素分布与向重力生长的关系：                                  。查看习题详情和答案>>

　　1.由于大雪，飞行员只得把飞机降落到另一座城市的一个飞机场。

　　______________ _____ the snow, the pilot had to land the plane at an airport in another city.

　　2.老师不会鼓励学生在考试前才温书至深夜，他们应该上课时专心听讲才对。

　　Teachers do not encourage students to pull an all night for exams. They should _____ _______during lessons.

　　3.当你遇到问题的时候不要放弃，试试其他方法。

　　Don’t _____ _____ when you have a problem, try another way.

　　4.她根据遗嘱获得了一大笔财产。

　　She bagged a fabulous fortune _________________ _____ the will.

　　5.我给你五美元请你帮我看下车。

　　I pay you 5 dollars to _____ _________ my car.

　　6.我穿了一件红外套以便他能很容易地看见我。

　　I put on a red coat _____ _____________he could see me easily.

　　7.妇女们带着孩子排队领取食物。

　　Women _____ _____ with children for the food.

　　8.每早他都骑车载我去上学。

　　Every morning he _____ _____ _____ _____ school.

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There was a little boy who got angry easily. His father gave him a bag of nails(钉子) and told him that every 16 he got angry, to drive a nail into the back wall. The first day the boy had 17 37 nails into the wall. Then he put fewer and fewer nails. He found it was　18 to be not angry than to drive those 19 into the wall. 　Finally the day came when the boy didn't get 20 at all. He told his father about it and the father suggested that the boy now pull out one nail for each day that he was able to be not angry. The days 21 and the young boy was finally able to tell his father that 22 nails were gone. The father took his son by the hand and led him to the 23　. He said, "You have done 24 , my son, but look at the holes in the wall. The wall will 25 be the same. When you say things 　26 , they leave a scar(伤疤) just like this one. You 27 put a knife in a man and draw it out. It won't matter 28 you say I'm sorry, the wound（伤口） is still there. A mental hurt is as bad as a physical one. Friends are a very rare jewel, indeed. They make you 29 and encourage you to succeed. They lend an ear, they share a word of praise, and they always　30　 to open their hearts to us.

C．how many times

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I lost my sight when I was four years old by falling off a box and landing on my head. Now I am thirty-two. I can vaguely(模糊地) 　1　 the brightness of sunshine and what color red is. It would be wonderful to see things again, 　2　 a disaster can do strange things to people. It happened to me the other day that I might not have come to love 　3　 as I do if I hadn’t been blind. I believe in life now. I am not sure that I would believe in it so 　4　. I don’t mean that I would prefer to go without my eyes. I 　5　 mean that the loss of 　6　 made me enjoy more of 　7　 I have now.
Life asks us to keep making 　8　 to reality. If a person is able to get ready for anything changeable his world will 　9　 mor

e meaningful. I became blind, but I was 　10　. My parents and my teachers saw 　11　 in me－a potential(潜力) to live, you might call it－which I didn’t see, and they make me fight it out with blindness.
The hardest 　12　 I had to learn was to believe in myself. That was what I had to do at least. If I hadn’t been able to do that, I would become a chair rocker for the 　13　 of my life. When I say I believe in myself I am not talking about simply the kind of self-confidence that helps me down an unfamiliar staircase 　14　. That is part of it. But I mean something bigger than that: A belief that I could deal with anything alone; that somewhere in the 　15　 there is a special place where I can make myself fit.
1. A. imagine       B. find             C. remember     D. guess
2. A. but           B. though               C. so           D. because
3. A. myself        B. life             C. eyes         D. blindness
4. A. that         B. therefore            C. happily      D. deeply
5. A. seldom        B. just             C. hardly           D. always
6. A. them      B. it                   C. blindness        D. light
7. A. that         B. what             C. which            D. where
8. A. moments      B. encouragements       C. improvements D. changes
9. A. become        B. change               C. look         D. end
10. A. brave        B. lucky                C. sad          D. wise
11. A. something    B. everything           C. nothing      D. anything
12. A. problem      B. experience           C. difficulty       D. lesson
13. A. rest     B. whole                C. need         D. last
14. A. lonely       B. alone                C. self         D. person
15. A. company B. group                C. society (社会)   D. family 查看习题详情和答案>>

　　I’m Millie.I’m 12　1　old.I have black　2　 and black hair.I　3　born in Beijing and I live 　4　 Hoping Road.I have a brother.　5　 name is Andy.I like　6　TV and Andy 　7　 listening to the radio.I have 　8　of good friends at school.My　9　 friend is Kitty.She is my classmate.She is a good student.She wants to be a doctor when she 　10　up.?
1.A.month　         B.months　           C.year　                      D.years?
2.A.mouth　         B.nose                   C.eyes　                      D.eye?
3.A.am                  B.is                       C.was                           D.are?
4.A.in                   B.on                            C.for                            D.with?
5.A.His                 B.He                     C.Her                           D.She?
6.A.watch              B.watches              C.to watch　                D.watching?
7.A.like                 B.love                   C.enjoys                       D.enjoy?
8.A.lot                  B.lots                    C.a lots                        D.lot a?
9.A.good 　          B.better                 C.best                          D.well?
10.A.gets               B.puts                   C.rings                         D.grows 查看习题详情和答案>>