1. By studying mineral grains found in material ranging from rocks to clay articles, previous researchers have already been able to identify reversals dating back 170 million years, including the most recent switch 730,000 years ago.(1991. 阅读. 1. Text 2)

【译文】通过研究在岩石、陶器等材料中发现的矿物颗粒，先前的研究者们已经能够确认距今一亿七千万年前发生的的两级转化现象，包括发生在73万年前的最近一次两级转化。

【析句】复合句。主句previous researchers have been able to identify reversals dating back...,including...。主句中，dating back...为现在分词作定语修饰reversals。主句前，by studying mineral grains...是介词短语作方式状语，grains后found in material为过去分词作定语修饰grains，而material又有ranging from to...现在分词作定语。

2. Out of our emotional experiences with objects and events comes a social feeling of agreement that certain things and actions are good and others are bad, and we apply these categories to every aspect of our social life—from what foods we eat and what clothes we wear to how we keep promises and which people our group will accept. (1991. 阅读. 1. Text 3)

【译文】与事物的感情经历使我们产生了一种社会认同感：对特定的事物和行为的好坏达成一致意见。并且将这种“好”与“坏”的分类应用于社会生活的方方面面，从我们吃的食物、穿的衣服到如何信守承诺以及与什么人为伍。

【析句】主句Out of our emotional experiences...comes a social feeling of agreement...,and we apply these categories to every aspect of our social life...。可以看出，主句由and连接的两部分组成，前句因为介词短语提前，所以用了倒装语序，而且主语 a social feeling of agreement后是that引导的定语从句。后一句中，破折号后的内容是对every aspect of our social life的强调和解释。

3. It gives high rewards to individuals who perform important tasks such as surgery, makes heroes out of individuals for unusual or dangerous achievements such as flying fighter planes in a war, and uses the legal penal system to make people afraid to engage in antisocial acts. (1991. 阅读. 1. Text 3)

【析句】从事重要工作的人比如医生，受到高额奖励;把冒着危险做出非凡壮举的人，比如战争中的战斗机飞行员，推举成英雄;并且运用严酷的刑法体系使人们不敢做出反社会行为。大学英语六级试题下载

【析句】主句由两个并列句组成，It gives high rewards to individuals,makes heroes out of individuals for...,and uses the legal peanal system to make...，三个并列的谓语动词分别是gives,makes和uses。第一句中，individuals后有who perform important tasks作定语从句修饰individuals。第三句中，包含四个短语use sth to do sth,make sb adj,afraid to do sth, engage in sth。