问题是有3个it,这3个it的指代都不一样,这不是造成指代不一致了吗?老版PREP2 第8题的语法解释
Ozone, a special form of oxygen that screens out harmful ultraviolet rays, reaches high
concentrations twelve miles above Earth, where it has long appeared that it was immune from
human influence; we have now realized, though, that emissions of industrial chlorofluorocarbons
deplete the ozone layer.
(A) has long appeared that it was immune from
(B) has long appeared to have been immune from
(C) has long appeared as being immune to
(D) had long appeared immune to
(E) had long appeared that it was immune to
句子结构:Ozone, …, reaches high concentrations … above Earth, where... ; we have now realized
that…
分号隔开意思并列的两个句子。第一个句子主语是oxygen由that引导的定语从句修饰,谓语是
reaches,where引导定语从句修饰Earth,该从句是主系表结构,appear作系动词,immune to human
influence是表语。
考点:动词形式、指代一致
1) 动词形式-过去完成时,很多情况下,过去时间由上下文表示出来,不需要表示过去时间的状语。
2) 指代一致,形式主语it指代了句子的真正主语(真正的主语在句子后部),因为有所指,所以句子
中如果再出现其它有所指的it,就使it指代不一致,是错误的用法。
(A) it has long appeard that中it是形式主语,后面的it是指Ozone,两个it指代对象不一致。
(B) appeared to have been immume中的现在完成时多余,因为前面has appeared已经表达了完成时
态。
(C) appear as being用法错误。
(D) 正确,appear用作系动词,immune是adj.,简洁明了。分号后面是have now realized,强调now,
用了现在完成时,分号前面的long强调与现在的对比,用过去的时态较合理。
(E) 两个it指代不一致。
-- by 会员 azhongzhong (2011/8/3 11:14:00)
哪里有3个it呀?不是只有2个吗?笔记上解释的很清楚啊