What is the main difference between the earlie
问题详情
What is the main difference between the earlier model and the new voice card？
A．The new one can identify itself by its ID squawk.
B．The new one Can produce beeps.
C．The new one needs the user to key in ID details.
D．The new one works only when it hears the password spoken by the user.请帮忙给出正确答案和分析，谢谢！
参考答案
正确答案：D
解析：利用题干中的特征词earliermodel和newvoicecard作为答案线索，同时注意备选项中出现的核心词/特征词ID．squawk，beeps，mdetails，这样发现答案相关句：Butthisearliertechnologycannotpreventfraudulentuseofstolencards．Thenewonecan．(前一句)Thispreventsfraudstersrecordingthebeeps，notingthecreditcarddetailsandthenplayingbacktheaudibleIDwhentheykeyinthedetailslater．ThenewvoicecardalsoidentifiesitselfbyitsIDsquawk，(可见早期的音卡也能通过ID呼叫来加以识别，因此A不是答案)butitwillnotthisuntilithasverifiedthelegitimateuser'spassword.but引导的转折句显然在暗示早期声卡和新的声卡的不同，因此判断D是答案。
