24题仔细体会C和B的区别 C说：即使猎物是静止状态下，这个beetle也是要相隔相同时间的来休息，然后加速去追击 这不仅说明它的视力没有问题（因为静止状态下，没有 rapidly changing visual information），而且还说明他只是体力有问题，因为他休息好速度就加快（ the beetle increases its speed after its next pause） B就没有C好了 B说：在追一个运动的虫子的时候，beetles能很快的做出反应（视力没有问题），无论是斜向上还是斜向下追击的是后，停留的频率总是相同的（频率相同，不好说这是不是体力问题）这不像C说的那样的明显。
From 1978 to 1988, beverage containers accounted for a steadily decreasing percentage of the total weight of household garbage in the United States. The increasingly widespread practice of recycling aluminum and glass was responsible for most of this decline. However, although aluminum recycling was more widely practiced in this period than glass recycling, it was found that the weight of glass bottles in household garbage declined by a greater percentage than the weight of aluminum cans.
Which of the following, if true of the United States in the period 1978 to 1988, most helps to account for the finding?A Glass bottles are significantly heavier than aluminum cans of comparable size.
B Recycled aluminum cans were almost all beverage containers, but a significant fraction of the recycled glass bottles had contained products other than beverages.
C Manufacturers replaced many glass bottles, but few aluminum cans, with plastic containers.
D The total weight of glass bottles purchased by households increased at a slightly faster rate than the total weight of aluminum cans.
E In many areas, glass bottles had to be sorted by color of the glass before being recycled, whereas aluminum cans required no sorting. 前提1：From 1978 to 1988, beverage containers accounted for a steadily decreasing percentage of the total weight of household garbage in the United States. The increasingly widespread practice of recycling aluminum and glass was responsible for most of this decline. aluminum and glass的回收----导致了 beverage containers 垃圾的比重减少 矛盾：铝的回收力度比玻璃更大，但是玻璃的垃圾重量比铝垃圾的重量减少更多
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发表于 2010-3-19 23:45:19
