写作篇：SAT考试每日一题 1

>>SAT考试：写作篇：SAT考试每日一题（1）

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Some plant pathologists have turned to geneticengineering to devise new ways of responding tobotanical diseases. Plant pathologist William Powell, for instance, teamed up with forest biologist ChuckMaynard to restore North America's population ofAmerican chestnut trees, which was decimated in theearly 1900s by a fungus known as chestnut blight. A fungus, C. parasitica, contributes to thegrowth of cankers on the trees' trunks; these cankers, in turn, prevent trees fromtransporting water from their roots to their branches and leaves. To render American chestnuttrees resistant to the blight, Powell and Maynard experimented with altering the geneticmakeup of the trees. The resultant genetically engineered trees are called Darling 4 Americanchestnut trees, and during the first 15 weeks after infection with chestnut blight, they growcankers that are much smaller than those that grow on American chestnut trees.

A.NO CHANGE

B.messed about with

C.tried some stuff out for

D.embarked on a journey of discovery regarding

答案：A

解析：

Choice A is the best answer because it maintains the formal, academic tone of the rest of the passage.

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