第二篇credit card only works when spoken to
　　a credit card that will not work unless it hears its owner's voice could become an important
　　weapon in the fight against fraud（欺騙）。the card requires users to give a spoken password that it recognizes using a built-in
　　voice-recognition chip.the idea is to prevent thieves using a stolen card or fraudsters using
　　someone else's credit card details to buy goods online.
　　a model built by engineers at beepcard in santa monica，california，represents the first
　　attempt to pack a microphone.a loudspeaker，a battery and a voice.recognition chip into a
　　standard.sized credit card.
　　they are not quite there yet：the card is the length and width of an ordinary credit card，but it
　　is still about three times as thick.the company now plans to make it thinner.
　　the voice card is based on an earlier beepcard technology designed to prevent fraud in
　　online transactions this earlier card has no microphone，but has a built.in loudspeaker that it
　　uses to“squawk”（發(fā)出叫聲）a voice id signal via a computer's microphone to an online server.
　　by verifying（證實）that the signal matches the card details，the server can establish that the
　　user is not simply keying in a credit card number but actually has the card to hand.the id code
　　changes each time the card is used in a pre—ordered sequence that only the server knows.
　　this prevents fraudsters recording the beeps，noting the card details and then playing back
　　the audible id when they key in the details later but this earlier technology cannot prevent
　　fraudulent use of stolen cards the new one can
　　the new voice card also identifies itself by its id squawk.but it will not do this until it has
　　verified the legitimate（合法的）user's spoken password thieves will be unable to use the card
　　because even if they knew the password they would have to be able to copy the owner's voice
　　with a high degree of accuracy
　　the challenge for beepcard has been to develop voice-recognition and audio circuitry that
　　can be powered by a mini battery embedded（嵌入的）in a credit card.to maximize battery life，
　　the electronics are only switched on when the card is being used.pressing a button on the card's
　　surface prompts it to utter “say your password ”in female voice if the voice—recognition software
　　proves that the password is authentic（真實的），it sends its id squawk which the server then
　　identifies.allowing the transaction to proceed
　　36 the voice credit card is an important invention because
　　a it can be made cost-effectively.
　　b it can leave voice messages，
　　c it makes online shopping easy
　　d it makes fraud difficult.
　　37 what is the problem which the model card？
　　a it is too large.
　　b it is toot hick
　　c it can't be used in online transactions
　　d it doesn't have a loudspeaker.
　　38 which of the following statements about the earlier card is true？
　　a its owner can change the id code freely
　　b its user does not need to key in the id number.
　　c it can record its user's spoken password.
　　d it still can be used by someone else after being stolen.
　　39 what is the advantage of the new voice card？
　　a it recognizes only its owner's spoken password.
　　b it doesn't need to work with an online server
　　c it requires less id information.
　　d it has a playback function
　　40 what can we learn from the last paragraph about the voice card？
　　a only female voice passwords could be recognized.
　　b further improvement should be made to extend battery life
　　c there is no limit to its application.
　　d female customers like to use it