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  3. The researchers put all the plants in a greenhouse to grow under normal conditions for forty days. Then, for fifteen days after

The researchers put all the plants in a greenhouse to grow under normal conditions for forty days. Then, for fifteen days after

admin2010-07-24  47
问题     The researchers put all the plants in a greenhouse to grow under normal conditions for forty days. Then, for fifteen days after that, the plants did not receive any【S1】______. The normal plants lost their green color. Finally, they lost their leaves. But the researchers say the【S2】______plants kept their leaves and their【S3】______.
    After the fifteen dry days, all the plants were watered again for a week. The transgenic plants returned to【S4】______growth, and their seed production was close to normal But the other plants all died.
    Rosa Rivera says the transgenic plants kept a【S5】______high water level. They also【S6】______to produce energy during the dry period, although at a reduced level. The amount of seeds they produced was close to normal. In addition, the researchers found that the plants could【S7】______on only thirty percent of the normal amount of【S8】______water. Yield loss was minor, they said.
    The【S9】______appeared late last year in the Proceedings of the National Academy of Sciences. The University of California has applied for patent【S10】______for the technology. The researchers expect to move forward with field testing of the transgenic tobacco in late August. They hope for similar results with crops like tomatoes, rice, wheat and cotton.

    A)similar        I)color
    B)keep           J)production
    C)water          K)level
    D)relatively     L)findings
    E)normal         M)continued
    F)survive        N)protection
    G)gained         O)irrigation
    H)transgenic
【S4】
选项
答案E
解析 此处空格应填形容词。前文意思是普通植物经过干旱之后面临死亡，而转基因植物长时间缺水后再进行补水依然能正常生长。
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