1. While warnings are often appropriate and necessary -- the dangers of drug interactions, for example -- and many are required by state or federal regulations, it isn’t clear that they actually protect the manufacturers and sellers from liability if a customer is injured. (1998.阅读.Text A)

　　【译文】警告往往是恰当且必要的，比如提醒药物反应带来的危险，有些警告也是州法或联邦法律所要求的。但事实上，若使用者受伤，法律条款并没有明确地保护生产商或销售者使其不必承担责任。

　　【析句】整句话的主干是主句+时间状语从句，主句中，it作形式主语，真正的主语是they actually protect...from liability，主句里又包括一个if引导的条件状语从句；while引导的时间状语从句中，有两个并列的分句warnings are...and many are...。破折号中间的内容属于插入语，抓主干时可暂时省略。

　　2. As personal injury claims continue as before, some courts are beginning to side with defendants, especially in cases where a warning label probably wouldn’t have changed anything. (1998.阅读.Text A)

　　【译文】随着人身伤害起诉案件一如既往地不断增加，一些法庭的判决开始偏向被告，尤其是在商品警告标签可能起不了多大作用的情况下。

　　【析句】整句话由主句some courts are beginning...+时间状语从句as personal injury claims...as before构成。其中，主句更为复杂，又包括一个where引导的定语从句，时态虚拟为语气wouldn't have changed...。

　　3. At the same time, the American Law Institute -- a group of judges, lawyers, and academics whose recommendations carry substantial weight -- issued new guidelines for tort law stating that companies need not warn customers of obvious dangers or bombard them with a lengthy list of possible ones.(1999.阅读.Text A)

　　【译文】与此同时，美国法律研究所——由一群法官、律师和理论专家组成，他们的建议分量极重——发布了新的民事伤害法令指导方针，宣称公司不必提醒顾客注意显而易见的危险，也不必连篇累牍地一再提请他们注意一些可能会出现的危险。

　　【析句】首先把破折号中间的插入语省略不看，句子的主干是the American Law Institute issued new guildelines for tort law，stating that ...是动名词引导定语从句，可以另写为which stated...。再看插入语中，包含一个whose引导的定语从句。正是各种从句的存在使得整句话显得复杂难解，也是考生在作文中应该借鉴之处。