练习册

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    plays 固定搭配.但要考虑主语的人称. 【查看更多】

     

    题目列表(包括答案和解析)

    材料：玉米的光合效率较水稻的高，这与玉米中磷酸烯醇式丙酮酸羧化酶（PEPC）有很大的关系。如何将玉米的这一种酶转移到水稻等植物上一直是植物生物学家的研究课　题之一。但实践证明，常规杂交育种手段很难如愿以偿。最近，有人利用土壤农杆菌介导法，将完整的玉米PEPC基因导入到了水稻的基因组中，为快速改良水稻的光合作用效率，提高粮食作物产量开辟了新途径。
    （１）玉米和水稻很难利用常规杂交手段杂交的原因是                         。
    （２）获得PEPC基因后，将其导入土壤农杆菌的质粒中，以获得重组质粒，需要的工具酶
    是                         和                     。
    （３）玉米PEPC基因在水稻细胞中成功表达的标志是                         ，该过程包括                 和                 两个阶段。
    （４）该技术定向改变了水稻的性状，这在可遗传变异的来源中属于___  _____。

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    根据下列句子的意思及所给的汉语提示，写出空缺处单词、固定短语或固定搭配的正确形式。
    【小题1】 Betty is a good friend of m________. We often help each other.
    【小题2】They have invited a_________(science) to give them a speech on space.
    【小题3】Mrs. Chan told us to write as_________(care) as we could.
    【小题4】 We Chinese sometimes__________(借) words from English when talking.
    【小题5】Victor__________(敲) the door before he walked into the room.

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    词语运用。（共5小题，每小题1分，计5
    根据下列句子的意思及所给的汉语提示，写出空缺处单词、固定短语或固定搭配的正确形式。
    1.Basketball                (发明) by a Canadian doctor, Jatnes Naismith.?
    2.Some students            (抱怨) that they have too much homework.?
    3.What made you so             (生气)??
    4. Look! The sick man is very tired, but he is still            _(练习走) without any help.
    5. By the time I arrived there, the film had        (开始)for about five minutes.

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    词语运用 （共5小题，每小题1分，计5分）
    根据下列句子的意思及所给的首字母、英语或汉语提示，写出空缺处单词或固定搭配的正确形式。
    1. We have English class every day except _________________(星期四).
    2. It’s not ________(surprise) that many tourists come to visit Shanghai every year.
    3. Chocolate is usually __________________ (children )favorite food.
    4. –How long may I _________ (借)the new book? --Two weeks.
    5. Jane began _______________(下象棋) when she was seven years old.

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    根据句意及所给提示，补全单词或用单词、固定短语、固定搭配的正确形式填空。

    1.You don’t like running. I don’t like running, e_________.

    2.Tomorrow will be my ____________ (十三) birthday.

    3.Don’t ____________ (touch) it. It’s dangerous!

    4.My father has ______________ (写) five books these years.

    5.I want to have a talk with you _____________________ (面对面地).

     

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