og 11 51和56的推导有何区别？（急！谁能帮忙看看？？）

bometic access-control systems-those using fingerprints, voiceprints,and so forth, to regulate admittace to restricted areas-work by degrees of similarity, not by identity. after all, even the same finger will rarely leae exactly identical prints. such systems can be adjusted to minimize refusal of access to legitimate access-seekers. such adjustments, however, increase the likelihood of admitting imposteors.

wihich of the following conclusions is most strongly supported by the information above?

a. if a biometric access-control system wee made to work by identity, it would not produce any correct admittance decisions.

b. if a biometric acces-control system reliably prevents impostors from beng admtted, it will sometimes turn away legitimate access-seekers

c. biometric access-control systems are appropriate only in situations in whichadmittance of impostors is less of a problem than is mistaken resusal of access.

d. no biometric access-control systems-based, for example, on numerical codes-are less likely than bioetric ones to adit impostors.

e. anyone choosing an access-control system should base the choice solely on the ratio of false refusals to false admittance.

key: (b)

这样算是逆否命题吗？如果出现if， if后面的句子应该是由此推导，还是被推导出的？

social scientists are underrepresented on the advisory councils of the national institutes of health(NIH).since these councils advise NIH directors and recommend policy, the underrepresentation of social scientists results in a relative lack of NIH financial support for research in the social sciences.

if the statement above are correct, they most strongly support which of the followings?

a. a significant increase in the size of NIH advisory councils would be required in order to increase the reresentation of social scientists on these councils.

b. a significant increase in the representation of social scientists on NIH adisory councils would result in an increase in NIH funding for social science research.

c.a significant increase in funding for social science research would result in improved policy recommendations to NIH directors

d. a significant increase in funding for the training of social scientists would result in an increase in the number of social scientistson NIH advisory councils.

e. a significant increase in the representation of social scientists on NIH advisory councils would have to preede any increase in the number of NIH directors who are social scientists.

key. (b)

这道题算是逆否吗？

谢谢了！

逆否?? 不知道是什么东东

如果是statement supports the answer choice, 那一定是要从文中来推的，如果是answer choice supports the statement, then the premise of the statement + the correnct answer = the conclision of the statement.

此上两题的答案都是应该由题目来推出的，其实这种题目可以理解成imply or inference 的类型，都是要找出原文中隐藏或想表达的信息