请教这个假设defender的题如何解？

liverich

Although the ratio of physicians to total population is about the same in the US and Canada, the US has 33 percent more surgeons per capita. Clearly, this is the reason people in the US undergo 40 persent more operations per capita than do Canadians. The explanation given above rests on an assumption that

a. patients in the US do not have a great need for surgery than do patient in Canada

b. the population of the US is not larger than that of Canada.

c. US patients somes travel to Canada for certain kinds of surgery

d. general practitioners in the US do not as a rule examine a patient who is a candidate fore surgery before sending the patient to a surgeon

e. there are no unnecessary surgical  operations performed in Canada.

[此贴子已经被作者于2006-11-27 22:01:55编辑过]

leepee

答案呢，D吗

maxtan

答案应该是美国的手术医生和加拿大手术医生平均做的手术差不多。

选项好像都不对

liverich

答案应该是A

LOUI1121

Although the ratio of physicians to total population is about the same in the US and Canada, the US has 33 percent more surgeons per capita. Clearly, this is the reason people in the US undergo 40 persent more operations per capita than do Canadians.

作者认为：美国比加拿大多33% more surgeons,是,美国比加拿大手术多40%的原因.

DEFENDER 排除其它原因,如A中,其他原因就是美国人比加拿大人需要的手术多.