1It was argued at the end of the 19th century that humans do not cry __13__ they are sad but they become sad when the tears begin to flow.
主干主语：It；谓语：was argued；宾语：that humans do not cry because they are sad but they become sad when the tears begin to flow
结构这是一个复合句。形式主语“It”指代后面的that从句。that从句是复合句，由“not...but...”连接两个并列分句：“humans do not cry because they are sad”和“they become sad when the tears begin to flow”。原因状语从句“because they are sad”修饰前一分句，时间状语从句“when the tears begin to flow”修饰后一分句。句子核心是詹姆斯的经典理论，指出情绪由身体反应引起而非相反。难点在于not...but...的并列结构和双重从句的嵌套，考研阅读中常考此理论的理解。
译文19世纪末有人认为，人类不是因为悲伤才哭泣，而是当眼泪流出来时才变得悲伤。
考点not...but...并列结构 · 原因状语从句与时间状语从句的嵌套
2In an experiment published in 1988, social psychologist Fritz Strack of the University of Würzburg in Germany asked volunteers to smile a pen either with their teeth – thereby creating an artificial smile – or with their lips, which would produce a(n) grim expression.
主干主语：Fritz Strack；谓语：asked；宾语：volunteers to smile a pen either with their teeth or with their lips
结构这是一个复合句。句首是时间状语“In an experiment published in 1988”，其中“published in 1988”是过去分词短语作后置定语，修饰“experiment”。主句是“social psychologist Fritz Strack...asked volunteers to smile a pen...”。“either...or...”连接两个并列的宾语补语，第一个“with their teeth – thereby creating an artificial smile”有插入成分“thereby creating an artificial smile”，第二个“with their lips, which would produce a(n) grim expression”中“which”引导非限制性定语从句，修饰“lips”。句子结构复杂在于多重修饰（时间状语+分词短语+插入成分+定语从句），容易混淆主谓宾关系和从句功能。考研阅读中此类长句常考语法和修饰关系。
译文1988年发表的一项实验中，德国维尔茨堡大学的社交心理学家弗里茨·斯特拉克让志愿者用牙齿或嘴唇夹住一支笔，前者会制造出人工微笑，后者会产生苦笑的表情。
考点过去分词短语作后置定语 · 插入成分与非限制性定语从句的区分