[求助] feifei 117&122

zs8373

117. A certain viral infection is widespread among children, and about 30 percent of children infected with the virus develop middle ear infections. Antibiotics, although effective in treating bacterial infections, have no effect on the virus. Yet when middle ear infections in children infected with the virus are treated with antibiotics, the ear often clear up.

Which one of the following most helps to explain the success of the treatments with antibiotics?

(A) Although some types of antibiotics fail to clear up certain infections, other types of antibiotics might provide effective treatment for those infections.

(B) Children infected with the virus are particularly susceptible to bacterial that infect the middle age.

(C) Many children who develop middle ear infections are not infected with the virus.

(D) Most viral infections are more difficult to treat than are most bacterial infections.

(E) Among children not infected with the virus, fewer than 30 percent develop middle ear infections.

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 operating 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 traditional 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.

(B) Twenty years ago, traditional power plants were producing 10 times more electric power than were photovoltaic plants.

(C) None of the recent technological advances in producing electric power at photovoltaic plants can be applied to producing power at traditional plants.

(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.

(E) The cost of producing electric power at photovoltaic plants is expected to decrease further, while the cost of producing power at traditional plants is not expected to decrease.

answer: B, D

zs8373

122你的意思是e,但我还是不太明白,可以不可以详细解释一下.

[此贴子已经被作者于2005-12-13 17:12:37编辑过]