69. Not only has the highway system affected the American economy by providing shipping routes, it has led to the growth of spin-off industries like service stations, motels, restaurants, and shopping centers.

　　【分析】本句為并列句。句子主干為Not only has the highway system affected the economy, it has led to the growth。not only but also 句型屬并列結構，意為 不僅 而且 ，but also 可以省略。 not only 在句首，句子謂語要用部分倒裝語序。

　　【譯文】公路系統不但通過提供運輸路線影響美國經濟的發展，還帶動了一批諸如加油站、汽車旅館、酒店、購物中心等相關行業的發展。

　　70. An educated mother, on the other hand, has greater earning abilities outside the home and faces an entirely different set of choices.

　　【分析】 本句為簡單句。句子主干為mother has abilities and faces choices。on the other hand是插入結構，分隔了主語和謂語，意為 另一方面 。

　　【譯文】從另一方面來講，一位受過教育的母親，有更多在外賺錢的本事，并且能面對一系列完全不同的選擇。

　　71. His results, to be presented at the conference on human-computer interaction in Vienna, Austria, in April, have surprised psychologists.

　　【分析】本句為簡單句。句子主干為 results have surprised psychologists。to be presented in April 是不定式短語作定語，修飾 results。

　　【譯文】他的研究結果令一些心理學家非常吃驚，他將在四月份奧地利維也納舉行的人機互動交流大會上為大家展現。

　　72. And economics, with its emphasis on incentives，provides guideposts that point to an explanation for why so many girls are deprived of an education.

　　【分析】本句為復合句。句子主干為economics provides guideposts。介詞短語 with its emphasis on incentives 是 economics 的伴隨狀語，分隔了主句的主語和謂語。that引導定語從句，修飾 guideposts。why引導賓語從句，作 explanation for 的賓語。

　　【譯文】因為本身強調激勵作用，經濟學對于大多數女孩被剝奪受教育權利的原因作出了解釋。

　　73. Many in-home jobs that used to be done primarily by women ranging from family shopping to preparing meals to doing voluntary work still need to be done by someone.

　　【分析】 本句為復合句。句子主干為 jobs need to be done。 that 引導定語從句，修飾 jobs。 ranging from to voluntary work 是現在分詞短語作定語，也修飾 jobs。

　　【譯文】許多過去主要由婦女做的家務活，例如購物、準備晚飯、做義務家務，現在仍然需要有人完成。

　　69. Not only has the highway system affected the American economy by providing shipping routes, it has led to the growth of spin-off industries like service stations, motels, restaurants, and shopping centers.

　　【分析】本句為并列句。句子主干為Not only has the highway system affected the economy, it has led to the growth。not only but also 句型屬并列結構，意為 不僅 而且 ，but also 可以省略。 not only 在句首，句子謂語要用部分倒裝語序。

　　【譯文】公路系統不但通過提供運輸路線影響美國經濟的發展，還帶動了一批諸如加油站、汽車旅館、酒店、購物中心等相關行業的發展。

　　70. An educated mother, on the other hand, has greater earning abilities outside the home and faces an entirely different set of choices.

　　【分析】 本句為簡單句。句子主干為mother has abilities and faces choices。on the other hand是插入結構，分隔了主語和謂語，意為 另一方面 。

　　【譯文】從另一方面來講，一位受過教育的母親，有更多在外賺錢的本事，并且能面對一系列完全不同的選擇。

　　71. His results, to be presented at the conference on human-computer interaction in Vienna, Austria, in April, have surprised psychologists.

　　【分析】本句為簡單句。句子主干為 results have surprised psychologists。to be presented in April 是不定式短語作定語，修飾 results。

　　【譯文】他的研究結果令一些心理學家非常吃驚，他將在四月份奧地利維也納舉行的人機互動交流大會上為大家展現。

　　72. And economics, with its emphasis on incentives，provides guideposts that point to an explanation for why so many girls are deprived of an education.

　　【分析】本句為復合句。句子主干為economics provides guideposts。介詞短語 with its emphasis on incentives 是 economics 的伴隨狀語，分隔了主句的主語和謂語。that引導定語從句，修飾 guideposts。why引導賓語從句，作 explanation for 的賓語。

　　【譯文】因為本身強調激勵作用，經濟學對于大多數女孩被剝奪受教育權利的原因作出了解釋。

　　73. Many in-home jobs that used to be done primarily by women ranging from family shopping to preparing meals to doing voluntary work still need to be done by someone.

　　【分析】 本句為復合句。句子主干為 jobs need to be done。 that 引導定語從句，修飾 jobs。 ranging from to voluntary work 是現在分詞短語作定語，也修飾 jobs。

　　【譯文】許多過去主要由婦女做的家務活，例如購物、準備晚飯、做義務家務，現在仍然需要有人完成。