Given the advantages of electronic money, you might think that we would move quickly to the cashless society in which all payments are made electronically. (1)_______ , a true cashless society is probably not around the corner. Indeed, predictions have been (2)_______ for two decades but have not yet come to fruition. For example, Business Week predicted in 1975 that electronic means of payment would soon “revolutionize the very (3)_______ of money itself,” only to (4)_______ itself several years later. Why has the movement to a cashless society been so (5)_______ in coming?

    Although electronic means of payment may be more efficient than a payments system based on paper, several factors work (6)_______ the disappearance of the paper system. First, it is very (7)_______ to set up the computer, card reader, and telecommunications networks necessary to make electronic money the (8)_______ form of payment. Second, paper checks have the advantage that they (9)_______ receipts, something that many consumers are unwilling to (10)_______. Third, the use of paper checks gives consumers several days of “float”—it takes several days (11)_______ a check is cashed and funds are (12)_______ from the issuer’s account, which means that the writer of the check can earn interest on the funds in the meantime. (13)_______ electronic payments are immediate, they eliminate the float for the consumer.

    Fourth, electronic means of payment (14)_______ security and privacy concerns. We often hear media reports that an unauthorized hacker has been able to access a computer database and to alter information (15)_______ there. The fact that this is not an (16)_______ occurrence means that dishonest persons might be able to access bank accounts in electronic payments systems and (17)_______ from someone else’s accounts. The (18)_______ of this type of fraud is no easy task, and a whole new field of computer science is developing to (19)_______ security issues. A further concern is that the use of electronic means of payment leaves an electronic (20)_______ that contains a large amount of personal data. There are concerns that government, employers, and marketers might be able to access these data, thereby violating our privacy.

答案精析：空处所填词为定语修饰that引导的同位语从句的表语occurrence，表示黑客入侵数据库并窃取信息的行为并非_______。而再根据上文中We often hear media reports that...得知，媒体经常报道这种新闻，所以黑客行为经常发生，即并非鲜见，C选项“并非不寻常”意义与之相近，为正确答案。

错项排除：黑客入侵数据库的行为不可能是安全的，所以A排除。这种行为也与是否自然无关，B排除。根据上文得知黑客入侵时有发生，所以也并非不清楚，D排除。