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题库 / Prep2007E2-SC-43
Although ice particles in the upper atmosphere benefit Earth in that they reflect and absorb solar radiation, acting as a global thermostat and thus keeping Earth from either burning up or freezing over, they also accelerate the destruction of the ozone layer by reacting with chlorofluorocarbons (CFC's).
acting as a global thermostat and thus keeping Earth from either burning up or freezing over, they also accelerate
acting as a global thermostat and thus keeping Earth either from burning up or freezing over, while also accelerating
act as a global thermostat and thus keep Earth from either burning up or freezing over, while also accelerating
they act as a global thermostat that thus keeps Earth either from burning up or freezing over, even though it also accelerates
they act as a global thermostat to thus keep Earth from either burning up or freezing over, but they also accelerate
B: while和alough都是连词，没有主句主语
C: 与B问题一样
DE : 结构变了，第一句是主句。意思错了不说，D的it，ethier or也有问题
语义应该是说，ice particles 能对地球有好处，act as后面的其实是对地球有好处的东西，所以DE不能用，因为DE转折应该是跟一个负面的东西。B没有谓语C没有主语？
B. error 1 - either-or formation is not parallel; error 2 - although...while formation is incorrect
C. error 1 - verb act does not modify the clause preceding it; error 2 - although...while formation is incorrect
either or只能排除B.D吧。。。登录 或 注册 后可以参加讨论