标题: prep1-63一点疑惑 [打印本页] 作者: slamshady 时间: 2010-5-7 19:32 标题: prep1-63一点疑惑 Unlike emergency calls that travel through regular telephone lines, where they thus automatically inform the operator of the location and phone number of the caller, cellular calls require emergency operators to determine the location of the caller. (A) lines, where they thus automatically inform the operator of the location and phone number of the caller, cellular calls require emergency operators to determine the location of the caller (B) lines and thus automatically inform the operator of the location and phone number of the caller, cellular calls require emergency operators to determine the location of the caller (C) lines, thus automatically informing the operator of the location and phone number of the caller, the location of the caller on a cellular phone has to be determined by the operator (D) lines, and thus automatically inform the operator of the location and phone number of the caller, emergency operators have to determine the location of the cellular phone caller (E) lines, thus automatically informing the operator of the location and phone number of the caller, emergency operators receiving a cellular call have to determine the location of the caller
有点不理解，为什么有了逗号，and后面就要补出主语they？真的有这样的说法吗？作者: jtrchina 时间: 2010-5-7 19:49
That is correct,at lesat in Gmat. The use of "and" can be classified as 2 ways: 1."and" without "," before indicates that a parallism exsists,which needs the formation of parallel parts to be identical. 2."and" with "," before adjoions 2 independent sentences,each including its own subject and verb,respectively.Here,there is only one exception:when a,b,c,and d appears,even though there is "," before "and",such form of sentence subjects to rule #1. Hope it helps!作者: slamshady 时间: 2010-5-7 23:37
嗯嗯。。。有道理，谢谢哈！