费费135题宝典中的一个问题

wcai

113, If you add a "not" in a, the reslut of the topic will not be necessory : if the parents do not prefer a reasonable level of academic quality  to any other factors, academically underachieving schools will not be forced to improve their academic offerings to attract students, on the other side, maybe the schools will attract the students  with greater sports opportunities or more convenient location.  so I think a is right.

wcai

120, I think the answer is d, because d can eliminate other factors  than clisthencis that may affect the resluts of the two kinds of children . right?

bajie24

120. In Europe, schoolchildren devote time during each school day to calisthenics. North American schools rarely offer a daily calisthenics program. Tests prove that North America children are weaker, slower, and shorter-winded than European children. We must conclude that North American children can be made physically fit only if they participate in school calisthenics on a daily basis.
Which one of the following is assumed in the passage?
(A) All children can be made physically fit by daily calisthenics.
(B) All children can be made equally physically fit by daily calisthenics.
(C) Superior physical fitness produces superior health.
(D) School calisthenics are an in indispensable factor in European children’s
(E) North American children can learn to eat a more nutritious diet as well as to exercise daily.

这题我也不明白

bajie24

113. The reforms to improve the quality of public education that have been initiated on the part of suppliers of public education have been insufficient. Therefore, reforms must be demanded by consumers. Parents should be given government vouchers with which to pay for their children’s education and should be allowed to choose the schools at which the vouchers will be spent. To attract students, academically underachieving schools will be forced to improve their academic offerings.
The argument assumes that
(A) in selecting schools parents would tend to prefer a reasonable level of academic quality to greater sports opportunities or more convenient location.
(B) improvement in the academic offerings of schools will be enforced by the discipline of the job market in which graduation students compete
(C) there is a single best way to educate students
(D) children are able to recognize which schools are better and would influence their parents’ decisions.
(E) schools would each improve all of their academic offering and would not tend to specialize in one particular field to the exclusion of others.

答案怎么会是A呢？