56. Ultimately, however, our basic design strategy is focused not simply on being “less bad” but on creating completely healthful materials that can be either safely returned to the soil or reused by industry again and again. (2006年6月)

【分析】本句为复合句。句子主干为our basic design strategy is focused not on being “less bad” but on creating healthful materials。that引导定语从句，修饰materials。however 意为“然而”，是插入成分。not…but…意为“不是……而是……”，连接两个介词短语。either…or…意为“或者……或者……”，表示并列结构。

【译文】然而最终，我们的基本设计目标不仅是简单地关注于“较低危害”，而是发明完全有益于健康的材料，这种材料或可以无害地回归土地，或可以被工业重复利用。

57. As you sleep you pass through a sequence of sleep states — light sleep, deep sleep and REM (rapid eye movement) sleep — that repeats approximately every 90 minutes. (2006年6月)

【分析】本句为复合句。主句主干为you pass through a sequence of sleep states。as引导时间状语从句，表示“当……时”。that引导非限制性定语从句，修饰a sequence of sleep states，that在从句中作主语。light sleep, deep sleep and REM (rapid eye movement) sleep 是插入成分，具体说明 states 的内容。

【译文】人们睡觉时经历了一连串的睡眠阶段——浅度睡眠阶段，深度睡眠阶段，快速眼动睡眠阶段——大约每90分钟重复一次。

58. You program the clock with the latest time at which you want to be wakened, and it then duly(适时地) wakes you during the last light sleep phase before that. (2006年6月)

【分析】本句为并列复合句。句子主干为You program the clock, and it wakes you。at which 引导定语从句，修饰 time，which 在从句中作时间状语，at+时间是固定搭配，所以 which 之前加介词 at，表示在某一具体时间点。句末的 that 指代 the latest time。

【译文】将闹钟调好至你想起床的时间，它便会适时地在之前的最后一个浅眠期将你叫醒。

59. Home builders can now use materials — such as paints that release significantly reduced amounts of organic compounds — that don’t destroy the quality of the air, water, or soil. (2006年6月)

【分析】本句为复合句。主句为Home builders can now use materials。such as… compounds是举例说明，作插入语。第一个 that 引导定语从句，修饰 paints;第二个 that 引导定语从句，修饰 materials。

【译文】房屋建造者们现在可以使用不破坏空气、水或土壤的材料，如释放少量有机物的涂料。

60. We’re giving people high-quality, healthful products and an opportunity to make choices that have a beneficial effect on the world. (2006年6月)

【分析】本句为复合句。主句为We’re giving people high-quality, healthful products and an opportunity to make choices。that 引导定语从句，修饰 choices，that 在从句中作主语。to make choices 作 opportunity 的定语。

【译文】我们提供高质量和健康的产品，提供做选择的机会，他们可以选择对世界有益的产品。

提醒：沪江考后放出2013年6月英语四级答案及真题下载信息