- UID
- 13562
- 在线时间
- 小时
- 注册时间
- 2003-10-9
- 最后登录
- 1970-1-1
- 主题
- 帖子
- 性别
- 保密
|
狒狒114,118,122請教
114. The number of North American children who are obese---that is, who have more body fat that do 85 percent of North American children their age---is steadily increasing, according to four major studies conducted over the past 15 years.
If the findling reported above is correct, it can be properly concluded that
(C) the number of North American children who are not obese increased over the past 15 years.
(D) over the past 15 years, the number of North American children who are inderweight has declined.
The correct is (C) but I can't understand why C is correct. I preferred (D) over (C)
118. There are about 75 brand of microwave popcorn on the market altogether, they account for a little over hald of the money from sales of microwave food products. It takes three mintues to pop corn in the microwave, compared to even minutes to pop corn conventionally. Yet by weight, microwave popcorn typically costs over five times as much as conventional popcorn. Judging by the popularity of microwave popcorn, many people are willing to pay a high price for just a little additional convenience.
Which one of the following statements, if ture, would call into question the conclusion in the passage?
(A) More than 50 percent of popcorn purchasers buy conventional popcorn rather than microwave popcorn.
(B) Most people who prefer microwave popcorn do so because it is less fattening than popcorn that is popped conventionally in oil.
The correct answer is (B). However, why (A) is incorrect?
122. Photovoltaic power plants produce electricity from sunlight. As a result of astonishing recent technological advances, the cost of producing electric power at photovoltaic power plants, allowing for both construction and operation costs, it one-tenth of what it was 20 years ago, whereas the corresponding cost for traditional plants, which burn fossil fuels, has increased. Thus, photovoltaic power plants offer a less expensive approach to meeting demand for electricity than do tranditional power plants.
The conclusion of the argument is properly drawn it which one of the following is assumed?
(A) the cost of producing electric power at traditional plants has increased over the past 20 years.
(D)Twenty years ago, the cost of producing electric power at photovoltaic plants was less than 10 times the cost of producing power at traditional plants.
The correct answer is (D), but I can't understand why (D) is correct cuz I can't find any clues from the statements. My answer was (A). |
|
京公网安备11010202008513号 京ICP证101109号 京ICP备12012021号
发表于 2003-12-20 21:20:00
楼主