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  3. Increasing numbers of farmers are growing genetically engineered crops. A new report also says that the total land area where su

Increasing numbers of farmers are growing genetically engineered crops. A new report also says that the total land area where su

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问题     Increasing numbers of farmers are growing genetically engineered crops. A new report also says that the total land area where such crops are grown is increasing.
    Genetic engineering is the technology of changing the genes of living things. Genes are parts of【B1】______ that control 【B2】______ and development. A changed gene directs a plant or other【B3】______ to do things it normally does not do. For example, a plant may be genetically engineered to【B4】______ insects.
    There is plenty of【B5】______ information about genetically engineered crops. Critics of genetic engineering say the technology is a threat to human health and the environment.
    The new report【B6】______ that farmers grew genetically engineered crops on more than 52 million hectares of farmland last year. That【B7】______ an increase in land area of 19 percent【B8】______ to the year before.
   【B9】______. Four countries grew 99 percent of all genetically engineered crops last year. The United States grew 68 percent of the world total. Argentina grew 22 percent. Canada was next with 6 percent.
    The report says soybeans were the most common genetically engineered crop. They were grown on 33 million hectares of farmland, Other common genetically engineered crops were com and cotton.
    【B10】______The scientists say the genes were found in wild corn growing in the mountains of southern Mexico.【B11】______.
【B1】
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