考研英语模拟试题及答案：阅读篇(1)_第2页

　　词汇注释

　　stuff 物质

　　preamble 开端

　　nook and cranny 排列

　　potency 力量

　　susceptible 易受感染的

　　predisposition 易患病的体质

　　难句讲解

　　1. They know that human DNA acts like a biological computer program some 3 billion bits long that spells out the instructions for making proteins， the basic building blocks of life.

　　[简析] 本句话的主干是“They know that…”。they 指的是前面句子中提到的scientists;第一个引导的是宾语从句，some 3 billion bits long修饰computer program，第二个that也修饰computer program;the basic building blocks of life是在解释proteins.

　　2. Anderson， who pioneered the first successful human gene-therapy operations， is leading the campaign to put information about DNA to use as quickly as possible in the treatment and prevention of human diseases.

　　[简析] 本句话的主干是“Anderson is leading the campaign…”。Who引导的非限定性定语从句，修饰Anderson;to put information…短语修饰campaign，其中的to use…作目的状语。

　　3. DNA in their hands has become both a blueprint and a drug， a pharmacological substance of extraordinary potency that can treat not just symptoms or the diseases that cause them but also the imperfections in DNA that make people susceptible to a disease.

　　[简析] 本句话的主干是“DNA has become both a blueprint and a drug”。in their hands修饰DNA;a pharmacological substance…是在解释前面的drug，其中的第一个that 引导的定语从句修饰pharmacological substance;第二个that引导的定语从句修饰imperfections.

　　4. And if scientists determine that a vital protein is missing because the gene that was supposed to make it is defective， they might be able to give the patient an artificial version of the protein.

　　[简析] 本句话的主干是“…they might be able to give the patient an artificial version of the protein”。If引导的是条件状语从句，其中的第一个that引导的是宾语从句，because引导的时原因状语从句;第二个that引导的定语从句修饰gene.