这道题的答案错了！

Q 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, house

Holds whose microwave oven has no built-in clock use 45 kilowatt-hours per year

Less. On average, than do comparable households shoes microwave oven is other-

Wise 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, onaverage, than do households that have a microwave oven.

B.     Microwave ovens with a built-in clock do not generally cost more to buy thanmicrowave 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.

gwd的一道题，答案是b，但是我觉得d更合适，d排除了它因，对d取非--“if Households whose microwave oven does not have a built-in clock do have a separate electric clock plugged in than households whose microwave oven has one”，so the household must use more 48kw electricity a year.

请大家发表一下自己的高见，多谢！

再加一道题，答案是e，拙见为b

The milk of many mammals contains cannabinoids, substances that are known to stimulate certain receptors in the brain. To investigate the function of cannabinoids, researchers injected newborn mice with a chemical that is known to block cannabinoides from reaching their receptors in the brain. The injected mice showed far less interest in feeding than normal newborn mice do. Therefore, cannabinoids probably function to stimulate the appetite.

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

A.     Newborn mice do not normally ingest any substance other than their

mothers’ milk.

B.     Cannabinoids are the only substances in mammals’ milk that stimulate the appetite.

C.     The mothers of newborn mice do not normally make any effort to encourage their babies to feed.

D.     The milk of mammals would be less nutritious if it did not contain cannabinoids.

E.      The chemical that blocks cannabinoids from stimulating their brain receptors does not independently inhibit the appetite.

再加一道题，答案是e，拙见为b

The milk of many mammals contains cannabinoids, substances that are known to stimulate certain receptors in the brain. To investigate the function of cannabinoids, researchers injected newborn mice with a chemical that is known to block cannabinoides from reaching their receptors in the brain. The injected mice showed far less interest in feeding than normal newborn mice do. Therefore, cannabinoids probably function to stimulate the appetite.

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

A.     Newborn mice do not normally ingest any substance other than their

mothers’ milk.

B.     Cannabinoids are the only substances in mammals’ milk that stimulate the appetite.

C.     The mothers of newborn mice do not normally make any effort to encourage their babies to feed.

D.     The milk of mammals would be less nutritious if it did not contain cannabinoids.

E.      The chemical that blocks cannabinoids from stimulating their brain receptors does not independently inhibit the appetite.

第一题支持d

B错误答案，无关

第二题我支持E

B：C是唯一的刺激的物质

文章是要证明C能刺激受体，采取的方法是，注射抑制C到达受体的物质。C是文章讨论的物质，其他东西out of scope。

取非，C是众多刺激受体的物质之一，这并未削弱结论。文章的结论就是C是那种刺激受体的物质。

对E取非。如果抑制剂本身会抑制受体，那么就不能说明C是该种物质。因为本意是想通过“抑制”这样一个过程来证明C就是刺激受体的东西。但是现在，“抑制”的产生有了另一种可能，即抑制剂本身产生的抑制作用，使得试验结论不可靠，从而削弱结论