几道PREP 请大侠指点 - ChaseDream

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
这题我怎么觉的选E呢

16.(27621-!-item-!-188;#058&003223)

Most of the world's supply of uranium currently comes from mines.It is possible to extract uranium from seawater, but the cost of doing so is greater than the price that uranium fetches on the world market.Therefore, until the cost of extracting uranium from seawater can somehow be reduced, this method of obtaining uranium is unlikely to be commercially viable.

Which of the following would it be most useful to determine in evaluating the argument?

(A) Whether the uranium in deposits on land is rapidly being depleted

(B) Whether most uranium is used near where it is mined

(C) Whether there are any technological advances that show promise of reducing the cost of extracting uranium from seawater

(D) Whether the total amount of uranium in seawater is significantly greater than the total amount of uranium on land

(E) Whether uranium can be extracted from freshwater at a cost similar to the cost of extracting it from seawater

C 为什么不对

20.(28411-!-item-!-188;#058&003617)

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.

这题C为什么对呢