原帖由 雪落无声17于 2006-8-19 13:25 发表
最后道改错题
A (chemical) element, (over) 90 of which( occurs) naturally on earth,is a (substance made up) of....
该选哪个?
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这个不难发现,错在OCCURS,因为后面的IS才是句子的谓语,(over) 90 of which( occurs) naturally on earth只是作为修饰的短语,所以应该将OCCURS改为OCCURING,并不能以动词的形式出现。