[求助]破解prep1,cr1-10,13谢谢！

10.   (25259-!-item-!-188;#058&001774)

Jennifer:  Video rental outlets in Centerville together handled 10,000 fewer video rentals in 1994 than in 1993.  The decline in rentals was probably due almost entirely to the February 1994 opening of Videorama, the first and only video rental outlet in the area that, in addition to renting videos, also sold them cheaply.

Brad:  There must be another explanation:  as you yourself said, the decline was on the order of 10,000 rentals.  Yet Videorama sold only 4,000 videos in 1994.

Which of the following, if true, would most seriously weaken the force of the objection that Brad presents to Jennifer's explanation?

(A) In 1994 Videorama rented out more videos than it sold.

(B) In 1994 two new outlets that rent but that do not sell videos opened in Centerville.

(C) Most of the video rental outlets in Centerville rent videos at a discount on certain nights of the week.

(D) People often buy videos of movies that they have previously seen in a theater.

(E) People who own videos frequently loan them to their friends.

13.   (26741-!-item-!-188;#058&002910)

Which of the following most logically completes the argument?

United States manufacturers currently produce most of the world's solar-power generators--most of which are exported to Europe.  However, European manufacturers are emerging and probably will ultimately capture much of the European market.  The United States government is funding initiatives intended to encourage use of solar power within the United States.  If these initiatives succeed in increasing the demand for solar-power generators in the United States, United States manufacturers will probably maintain significant production levels, since __________.

(A) some United States manufacturers have been substantially increasing their output over the last several years

(B) the efficiency of solar-power generators in converting energy from the Sun into electric power is not improving as fast as it once did

(C) just as European manufacturers enjoy certain competitive advantages in Europe, so do United States manufacturers in the United States

(D) European governments are currently undertaking initiatives to stimulate the use of solar power within Europe

(E) the current market for solar-power generators in the United States is very limited

10题答案是E,但为什么A不对呢，我是觉得2个都有weaken作用，

13题答案是C,但为什么E不对呢，

请高手指教！谢谢

10题答案是E,但为什么A不对呢，我是觉得2个都有weaken作用，

13题答案是C,但为什么E不对呢，

请高手指教！谢谢

这题应该是Ｃ。因为美国制造商在美国有优势，才能保证他们能占领美国市场。否则即使市场开发了，也可能被欧洲厂商抢去。Ｅ是无关，如果美国市场有限，那么美国制造商占领了也没用阿！再说提干已经给出了.  If these initiatives succeed in increasing the demand for solar-power generators in the United States，所以不存在市场大小问题。