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).
但对于这道题,语法笔记中说: “这个句子中的分词结构 acting as...只能修饰 in that they reflect and absorb solar radiation,不存在歧 义。如果要往后修饰主句 they also accelerate...,那么必须在 Although...从句与 acting as...之间加上 连词,因为这都是修饰主句的状语(前者是状语从句,后者是分词结构状语),没有连词无法并列存在。”
题目如下~ 43. (26724-!-item-!-188;#058&003285) 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). (A) acting as a global thermostat and thus keeping Earth from either burning up or freezing over, they also accelerate (B) acting as a global thermostat and thus keeping Earth either from burning up or freezing over, while also accelerating (C) act as a global thermostat and thus keep Earth from either burning up or freezing over, while also accelerating (D) they act as a global thermostat that thus keeps Earth either from burning up or freezing over, even though it also accelerates (E) they act as a global thermostat to thus keep Earth from either burning up or freezing over, but they also accelerate