黑暗版阅读真题解析1997Text 3

难句解析：

①The phrase "substance abuse" is often used instead of "drug abuse" to make clear that substances such as alcohol and tobacco can be just as harmfully misused as heroin and cocaine.
▲句子的主干是句子的前半部分The phrase "substance abuse" is often used... to make clear...，to make clear that...是动词不定式作状语，表示目的。that后面接的是宾语从句作动词make clear的宾语。
△注意make+sht.+adj.：make sth. clear，这里因为sth.是一个that引导的从句，所以放在了形容词clear的后面。另外注意as... as的用法。

②We live in a society in which the medicinal and social use of substances(drugs) is pervasive: an aspirin to quiet a headache, some wine to be sociable, coffee to get going in the morning, a cigarette for the nerves.
▲句子的主干就是We live in a society...，后面which引导定语从句in which the medicinal and social use of substances(drugs) is pervasive，修饰society。冒号后面的部分是并列关系的名词词组，用来举例说明前面提出的观点，开始可以略去不看。
△注意冒号后面列举的前三个名词词组中的动词不定式都相当于定语成分，修饰前面的中心名词，表示其功效。

③Dependence is marked first by an increased tolerance, with more and more of the substance required to produce the desired effect, and then by the appearance of unpleasant withdrawal symptoms when the substance is discontinued.
▲句子的主干结构是Dependence is marked first by..., and then by...，其逗号隔开的成分是with+n.+过去分词：with more and more of the substance required to produce the desired effect作状语，用来进一步解释药物依赖的第一种表现。when the substance is discontinued是表示时间的状语从句。
△注意and连接两个by开始的介词词组是并列关系，这样就能抓住句子的主干了。另外注意名词在这里的特殊意义：dependence指"对药物的依赖"，withdrawal的意思是"停止用药"。

④Psychoactive substances are commonly grouped according to whether they are stimulants, depressants, or hallucinogens.
▲这是一个简单句。句子的主干部分是Psychoactive substances are... grouped according to...，使用了被动语态。其中whether引导宾语从句whether they are stimulants, depressants, or hallucinogens作介词according to的宾语。
△group这里用作动词，是"分类"的意思。