78. Traffic control systems and methods of construction developed under the interstate program soon influenced highway construction around the world, and were invaluable in improving the condition of urban streets and traffic patterns.

　　【分析】本句为简单句。句子主干为 system and methods influenced construction and were invaluable。第二个and连接两个并列谓语。developed under the interstate program 是过去分词短语作后置定语，修饰 systems和methods。

　　【译文】在州际公路项目下发展的交通控制系统以及建筑方式很快影响到了世界范围公路的建设，并为改善城市街道和交通模式起到了重要作用。

　　79. By opening the North American continent, highways have enabled consumer goods and services to reach people in remote and rural areas of the country, spurred the growth of suburbs, and provided people with greater options in terms of jobs, access to cultural programs, health care, and other benefits.

　　【分析】本句为简单句。句子主干为highways have enabled to reach people, spurred the growth, and provided people with options。By opening the North American continent 是方式状语。

　　【译文】通过开通北美洲路线，公路使得消费品和服务能够到达住在边远地区和农村地区的人们那里，刺激周边地区经济发展，为人们提供更多选择，如工作、文化活动、保健及其他福利。

　　80. The technological advances made it possible for the middle classes to enjoy what had once been affordable only to the very rich.

　　【分析】本句为复合句。句子主干为technological advances made it possible to enjoy 。it作形式宾语，真正的宾语是to enjoy what had once been affordable only to the very rich。what 引导的从句作enjoy的宾语。possible 是made的宾语补足语。

　　【译文】技术上的进步使中产阶级也能享受到那些原来只有有钱人才负担得起的东西。

　　81. The clock, called Sleep Smart, measures your sleep cycle, and waits for you to be in your lightest phase of sleep before rousing you.

　　【分析】本句为简单句。句子主干为 The clock measures cycle and waits，两个谓语并列平行。called Sleep Smart 是过去分词短语作定语，修饰 clock, 表示被动。现在分词短语 before rousing you 作时间状语，相当于一个从句：before it rouses you。

　　【译文】这种称做 睡精灵 的闹钟可以测量睡眠周期，等待人们进入浅眠状态后才将其唤醒。

　　78. Traffic control systems and methods of construction developed under the interstate program soon influenced highway construction around the world, and were invaluable in improving the condition of urban streets and traffic patterns.

　　【分析】本句为简单句。句子主干为 system and methods influenced construction and were invaluable。第二个and连接两个并列谓语。developed under the interstate program 是过去分词短语作后置定语，修饰 systems和methods。

　　【译文】在州际公路项目下发展的交通控制系统以及建筑方式很快影响到了世界范围公路的建设，并为改善城市街道和交通模式起到了重要作用。

　　79. By opening the North American continent, highways have enabled consumer goods and services to reach people in remote and rural areas of the country, spurred the growth of suburbs, and provided people with greater options in terms of jobs, access to cultural programs, health care, and other benefits.

　　【分析】本句为简单句。句子主干为highways have enabled to reach people, spurred the growth, and provided people with options。By opening the North American continent 是方式状语。

　　【译文】通过开通北美洲路线，公路使得消费品和服务能够到达住在边远地区和农村地区的人们那里，刺激周边地区经济发展，为人们提供更多选择，如工作、文化活动、保健及其他福利。

　　80. The technological advances made it possible for the middle classes to enjoy what had once been affordable only to the very rich.

　　【分析】本句为复合句。句子主干为technological advances made it possible to enjoy 。it作形式宾语，真正的宾语是to enjoy what had once been affordable only to the very rich。what 引导的从句作enjoy的宾语。possible 是made的宾语补足语。

　　【译文】技术上的进步使中产阶级也能享受到那些原来只有有钱人才负担得起的东西。

　　81. The clock, called Sleep Smart, measures your sleep cycle, and waits for you to be in your lightest phase of sleep before rousing you.

　　【分析】本句为简单句。句子主干为 The clock measures cycle and waits，两个谓语并列平行。called Sleep Smart 是过去分词短语作定语，修饰 clock, 表示被动。现在分词短语 before rousing you 作时间状语，相当于一个从句：before it rouses you。

　　【译文】这种称做 睡精灵 的闹钟可以测量睡眠周期，等待人们进入浅眠状态后才将其唤醒。