[求助]GWD 24-18

Most household appliances use electricity only when in use. Many microwave ovens, however, have built-in clocks and so use some electricity even when they are not in use. The clocks each consume about 45 kilowatt-hours per year. Therefore, households whose microwave oven has no built-in clock use 45 kilowatt-hours per year less. On average, than do comparable households whose microwave oven is otherwise similar but has a built-in clock.

Which of the following is an assumption on which the argument depends?

A)    Households that do not have a microwave oven use less energy per year, on average, than do households that have a microwave oven.

B)    Microwave ovens with a built-in clock do not generally cost more to buy than microwave ovens without a built-in clock.

C)    All households that have a microwave oven also have either a gas oven or a conventional electric oven.

D)    Households whose microwave oven does not have a built-in clock are no more likely to have a separate electric clock plugged in than households whose microwave oven has one

E)    There are more households that have a microwave oven with a built-in clock than there are households that have a microwave oven without a built-in clock.

I choose D...But I am not sure........ I can not find this question disscussed..

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到底是选Ｄ还是选Ｅ？Ｅ好象讲不通啊．

on average前面是逗号!

选D

日常生活常识的解释:

电子钟的用途就是让家电到时候会停止工作(节能).

很自然,要想有电子钟的电烤炉比无电子钟的烤炉仅仅多个电子钟的耗电量.自然是不能给无电子钟的烤炉加装电子钟.(哈哈,不会停的烤炉东西烤糊了了)

同样道理,会自动停的充电器和不会自动停的充电器,大家明白否??