求教2题逻辑 test18-13，20-11

iselibra

18-13
Canadians now increasingly engage in “out-shopping,” which is shopping across the national border, where prices are lower. Prices are lower outside of Canada in large part because the goods-and-services tax that pays for Canadian social services is not applied.
Which one of the following is best supported on the basis of the information above?
(A) If the upward trend in out-shopping continues at a significant level and the amounts paid by the government for Canadian social services are maintained, the Canadian goods-and-services tax will be assessed at a higher rate.
(B) If Canada imposes a substantial tariff on the goods bought across the border, a reciprocal tariff on cross-border shopping in the other direction will be imposed, thereby harming Canadian businesses.
(C) The amounts the Canadian government pays out to those who provide social services to Canadians are increasing.
(D) The same brands of goods are available to Canadian shoppers across the border as are available in Canada.
(E) Out-shopping purchases are subject to Canadian taxes when the purchaser crosses the border to bring them into Canada.
这题答案是A，我不明白的是，out-shopping的增加和加拿大政府提高关税并没有必然关系阿。这个逻辑看不出来，希望大家来指教。

20-11
In malaria-infested areas, many children tend to suffer several bouts of malaria before becoming immune to the disease. Clearly, what must be happening is that those children’s immune systems are only weakly stimulated by any single exposure to the malaria parasite and need to be challenged several times to produce an effective immune response.
Which of the following, if true, most seriously undermines the explanatory hypothesis?
(A) Immediately after a child has suffered a bout of malaria, the child’s caregivers tend to go to great lengths in taking precautions to prevent another infection, but this level of attention is not sustained.
(B) Malaria is spread from person to person by mosquitoes, and mosquitoes have become increasingly resistant to the pesticides used to control them.
(C) A certain gene, if inherited by children from only one of their parents, can render those children largely immune to infection with malaria.
(D) Antimalaria vaccines, of which several are in development, are all designed to work by stimulating the body’s immune system.
(E) There are several distinct strains of malaria, and the body’s immune response to any one of them does not protect it against the others.
这一题的答案是E，那么D为什么不可以，这种疫苗同样不一定要让children去感染malaria阿？

拜谢大家了

dandan74

18-13：考数字关系，A这个选项中有个等式关系，
       购买商品的数目*tax rate = total amount.
A说 totol amount 不变，又题意 购买商品的数目在下降，所以必须提高tax rate.

20-11: 注意focus再提的结论：those children’s immune systems are only weakly stimulated by any single exposure to the malaria parasite and need to be challenged several times to produce an effective immune response.
想想D能weaken吗？原题的结论是说因为 weakly stimulated by single exposure. D无关

iselibra

明白了
谢谢dandan74