考研英语阅读理解真题名师点评 第2篇

　　难句解析：

　　1. There are about 105 males born for every 100 females, but this ratio drops to near balance at the age of maturity, and among 70-year-olds there are twice as many women as men。

　　【结构分析】 本句由三个分句构成。第一个分句是“There are about 105 males born for every 100 females”，一个“there be”句型；第二个分句“but this ratio drops to near balance at the age of maturity”是一个简单句；第三个分句是一个“there be”结构。

　　2. Again, differences between people and the opportunity for natural selection to take advantage of it have diminished。

　　【结构分析】 本句要注意的是有两个主语，分别是“differences between people”和“the opportunity for natural selection to take advantage of it”。

　　3. The grand mediocrity of today—everyone being the same in survival and number of offspring—means that natural selection has lost 80% of its power in upper-middle-class India compared to the tribes。

　　【结构分析】 本句的主干是“The grand mediocrity means that＋宾语从句”。其中“compared to the tribes”是分词结构作状语。破折号中间“everyone being the same in survival and number of offspring”是典型独立主格结构做插入语，其中“survival”和“number of offspring”都是介词“in”的宾语。