练习册

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    第一课时 词汇突破.聚焦语法 在学生预习单词的基础上,通过自学.互学.老师导学等方式扫除单词障碍,在学生谈论自己的好恶中引出本单元的定语从句. 【查看更多】

     

    题目列表(包括答案和解析)

    （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Ca 2+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：                                  。

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    阅读短文，根据中文填写适当的单词，使意思完整，每空一词。

    　　“For those who have never been to Tibet, Tibet is a 　　1　　(梦想); for those who have ever been there, Tibet is a memory．”said Li Wan, a graduate from Zhongshan University．

    　　Ms．Li became interested in Tibet after having worked in a company for less 　　2　　(比……)three months．　　3　　(自从)1998, Li has been spending 　　4　　(大部分)of her time on the challenge －she has got to almost every 　　5　　(角落)of Tibet during the 8 years．

    　　Li’s 　　6　　(第一)trip to Tibet was only out of her loving freedom．She entered Tibet along the Yunnan-Tibetan road．Although she couldn’t say a word of Tibetan language, this did not really 　　7　　(阻止)her from talking with local people successfully．“To me, they are free, 　　8　　(友好的), happy and close to nature．People should live in this way, singing while 　　9　　(工作), dancing while living,”Li said．

    　　Li describes Tibet in words and 　　10　　(照片)．“My goal in the next ten years is to make a good documentary．”said Li．

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    根据短文内容和所给的中文提示，在空白处填入单词。每空限填一词。

    　　Colors have their own ways of saying things in many everyday American expressions．

    　　Red is a hot color．Americans may say they are red-hot that means they are very 　　1　　(生气的)about something．Fast loud 　　2　　(音乐)is popular with many people．They may say it is red hot．

    　　Pink is a lighter kind of red．People sometimes say they are in the pink when they are in good health．The expression was 　　3　　(第一次)used in America at the beginning of the 20th century．It probably 　　4　　(来自)from the fact that many babies are 　　5　　(出生)with a nice pink color that shows that they are in good health．

    　　Blue is a 　　6　　(凉爽的)color．The color green is natural for 　　7　　(树)and grass．But it is an unnatural color for humans．A 　　8　　(人)who has a sick feeling stomach may say he feels a little green．Sometimes one may be upset 　　9　　(因为)he does not have something as nice as a friend has, he may say he is green with envy(妒忌)．The color black is used often in expressions．People 　　10　　(描写)a day in which everything goes wrong as a black day．

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    Even Sue, the top student in Class 1, Grade 9．She went to see Sigmund Friend for help．Look at Sue's profile and help Sigmund Friend complete his notes with as much information as you can．

    甚至九年级一班最好的学生苏也遇到一些问题，她向西格蒙德求助。请看苏的简介。用你所得到的尽可能多的信息，帮西格蒙德完成笔记。

    　　Wang Yifang, Sue

    　　My English name is Sue．I am a Grade 9 student and I am very clever．I love English, Maths and Science．I study hard and I always do well in exams．I an the top student in my class．However, I am not very good at sport．I cannot run fast and I hate swimming．

    　　王仪芳，苏

    　　我的英文名字叫苏。我是一个九年级的学生，我很聪明。我喜欢英语、数学和自然科学。我学习很用功，每次考试成绩都很好。我是班上最好的学生。可是，我不擅长体育。我跑的不快，而且我讨厌游泳。

    　　Wang Yifang, Sue

    　　Name：Wang Yifang, Sue

    　　Favourite subjects：English,(1)________ Maths, Science

    　　First problem：Not good at(2)________－can't(3)________ and(4)________．

    　　Advice：just try(5)________ in PE lessons, enjoy the(6)________．

    Second problem：Does not have many(7)________－classmates(8)________ her and call her‘Bookworm’．

    　　Advice：Talk to your(9)________ when feeling sad and share your(10)________ with her,(11)________ attention to those students who laugh at you and(12)________ your school work．

    　　王仪芳，苏

    　　姓名：王仪芳，苏

    　　最喜欢的学科：英语、数学和自然科学

    　　第一个烦恼：不擅长________不能________和________。

    　　建议：努力________在体育课上，喜欢________。

    　　第二个烦恼：没有太多的________。同学们嘲笑她________。

    　　建议：当你感到疲劳时，同________谈谈。或和她分担你的________。________嘲笑你的学生，并且________你的学校生活。

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    根据短文内容和所给中文提示，在空白处填入单词。每空限填一词。

    　　US President Obama gave a TV speech to his country’s students on the 　　1　　(第一)day of school．He made it from a 　　2　　(教室)in a high school．He told them to study as 　　3　　(努力)as they could．

    　　“NO matter(无论)what you want to do with your life, you will need an education, ” he said．

    　　“This isn’t just important for your own life and your own future．It will 　　4　　(决定)the future of this county．”

    　　Obama also said that school is not always 　　5　　(容易)．The challenges(挑战)of life make school a difficult time．

    　　“Maybe you can’t get your Parents’ 　　6　　(帮助)．Maybe someone 　　7　　(要求)you to go something wrong．But there is no excuse for not doing your homework of for not 　　8　　(尝试)．Your attitude(态度)toward yourselves and your education is　　　9　　(最)important．”

    　　Students shook 　　10　　(手)with Obama at the end of the class．

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