[求助]prep1-13, prep1-20求助

13

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

这个我选成了d，答案c应该怎么理解呢？

For years the beautiful Renaissance buildings in Palitito have been damaged by exhaust from the many tour buses that come to the city.  There has been little parking space, so most buses have idled at the curb during each stop on their tour, and idling produces as much exhaust as driving.  The city has now provided parking that accommodates a third of the tour buses, so damage to Palitito's buildings from the buses' exhaust will diminish significantly.

Which of the following, if true, most strongly supports the argument?

(A) The exhaust from Palitito's few automobiles is not a significant threat to Palitito's buildings.

(B) Palitito's Renaissance buildings are not threatened by pollution other than engine exhaust.

(C) Tour buses typically spend less than one-quarter of the time they are in Palitito transporting passengers from one site to another.

(D) More tourists come to Palitito by tour bus than by any other single means of transportation.

(E) Some of the tour buses that are unable to find parking drive around Palitito while their passengers are visiting a site.

不明白……

20题明白了，我原来把idle就理解成parking了……

13题是不是这个意思，如果鼓励solar generator，就会导致美国保持signigicant production level而不是欧洲，所缺少的条件是美国生产商有competitive advantage，如果没有这个条件，美国productin level可能会不变因为欧洲的优势会打败美国生产商，所以c是一个假设前提。

第13题的答案E为什么不对呀？

现在美国的solar-power generators市场有限，在成功的刺激了美国本土市场后，生产产商才有可能继续保持它们的生产产能：即把丢掉欧洲市场后富裕的生产产能，用于供给美国本土的需求。

got it

谢谢！明白了！