单项选择题

Genes that control factors such as size, color and shape determine the differences in fruit. And now that scientists have discovered how to detect different genes, farmers can hand over a young and tender branch to have its genes checked prior to planting. It works the same way as a detective (侦探) checking finger-prints. Once farmers know which trees are good and which are bad, they can discard the bad ones. Farmers can even create new varieties according to their individual tastes.
In the past three years, tens of thousands of tests were carried out to determine the genetic (基因的) features of fruit. Zhang, a Chinese scientists, showed a photo of a DNA (脱氧核糖核酸)-test and pointed to the shining lines on it, saying that the lines were genetic signs that tell us what a tree’s fruit will be like. For example, the ordinary pear tree bears fruit after four years. But now it only takes a month to test the DNA from a young leaf and a farmer will know everything about its fruit. By mixing different types of trees with suitable genes, farmers can create whatever fruit trees they want.

The passage tells us that the new genetic technology will enable farmers to()

A. increase the DNA of a fruit tree
B. improve the quality of fruit
C. make use of the shining features of fruit
D. change the cycle of fruit production


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C.第三世界国家所需的外汇可以通过矿产和热带农作物的出口。
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参考答案:Taiwan,China
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6.单项选择题China’s historic drive toward modernization first made headlines in the Western news media in the late 1970’s.()

A.中国历史性地向现代化奋进,在20世纪70年代末首次成为西方新闻媒介的头条新闻。
B.20世纪70年代末中国奔向现代化引起了西方媒体的广泛关注。
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参考答案:summer schedule changes