21. Having an exceptional beautiful mountain range and heavy winter snowfall,the International Olympic Committee choose Salt Lake city as the site of the 2002 Winter Olympics.

　 Because it has an exceptionally beautiful mountain range and heavy winter snowfall,Salt Lake city was chosen by the International Olympic Committee

　　点评：一种常考题型，因果关系的反映。由于Because的后面的it指Salt Lake city,故后半句主语开头必为Salt Lake city。

　　22.The marathon runner’s early burst of speed had been exciting to some,she was slower after several miles.

　　had been excitihg to some;however,she was

　　点评：句子语气其实也是这种题的关键之一。该句表转折，且是向不好方向转折，前面没有Although等。所以在句中用“however+分号”，呵呵，放之于四海皆准的真理。

　　23.(常考题：对比)The annual income of the average African citizen is 211 dollars,the average American’s income is almost 27591 dollars.

　　dollars,yet the average American’s income is

　　点评：对比题，所以要体现对比的语气。原句run-on了.所以正确答案中间用了yet这个词(和however差不多)。 记住此类题，比较常考

　　24.Although the CWS win more often than the CC,Chicago residnets,who are historically mid(此处不清晰) baseball fans,prefer the CC。

　　Right!

　　点评：使用正常的语序

　　25.Because the lens have UV protection,nearly all UV rays are prevented from reaching the wearer’s eyes.

　　protection,they prevent nearly all UV rays from reaching the wearer’s eyes.

　　点评：prevent sth/sb from doing sth. 老句型了。。。同时注意主语为lenses,所以直接用they。 一般用主动态多余被动态(“顺”比“逆”好)

　　26. The hills in SBC,like neighboring SLOC,is the home to some of C’s best vineyards.

　　the hills of neighboring SLOC,are

　　点评：hills要和hills对比才对称，be动词用复数。“of neighboring”这个用法可以记一下。

　　27(常考题：并列)Nurses and anesthesiologists are both essential in the operating room,and the anesthesiologists would keep the patient sedated while the nurses would assist and support the surgeon.

　　the anesthesiologists to keep the patient sedated and the nurses to assist and support

　　点评：anesthesiologists和nurses为并列关系，所以用“…to… and…to…”避免run-on。记住这种形式，考得比较多，大家做题时多注意类似题目

　　28.The sausage served at the end of the meal was more flavorful than any of the other pastas I had tasted;probably because it was roasted in its own juices.

　　was more flavorful than any of the pastas I had tasted,probably because

　　点评：pastas不是sausage，故谈到pastas用“any of pastas”不用“any other”。由于后半句谈原因，所以和前面是有联系的，中间用逗号。

　　29.When a bacterial culture is handled in an environment that is not appropriately sterilized,they can be introducing new organisms,ruining the culture.

　　When a bacterial culture is handled in an environment that is not appropriately sterilized,new organisms can be introduced,ruining

　　点评：对这个题我比较无语。。。。。。

　　30.The hawks’ nest,wedged into an apartment building’s facade,was a rather unique sight in Chicago;they became such an attraction that several book were written about them and tourists came from all over the country to see them.

　　the hawks,after several books were written about them,became such an attraction that

　　由于最后代词是“them”，可见所指为复数名词。而第一句主语为nest, 所以可见第二局主语不是网而是鹰。故正确答案不用代词为主语，而是将“they”指明，换成“hawks”

　　31.(常考题：并列)The major complaints professors have about teaching is that they have challenging research to complete and must also work hard to hold student interest.

　　are that they have challenging research to complete and must also work hard to hold student interest

　　点评：主谓一致性要保持，同时使用并列结构。

　　32.Having achieved fame, widespread acclaim,as well as continued relevance,DS is considered to be a classic American movie.

　　Having achieved fame,widespread acclaim,and continued relevance

　　点评：用动名词“Having”没错。但能用and就不用as well as(这似乎又是一条规律)，and前有无逗号无所谓。

　　33.For as many as 9 months or more,Thad Carthart lived in Paris.

　　For more than 9 months

　　点评：不说了，简洁为上!九个月或九个月以上就是“九个月以上”

　　34.Many home owners in the northern states use a window sealant,for it will prevent heat loss in the winter.

　　that will prevent

　　点评：谈原因，从句有时候更简洁。

　　35.The runners coming this far,they decided to push through the very strenuous final mile of the marathon.

　　Having come this far,the runners

　　点评：记住这个句式，Having done sth,XX…不是说它有知识上的意义(大家肯定早就知道了)，只是说它正确的频率相当高。同时原句没有转折语气就不要用转折词。