问题 单项选择题

Questions 84-90 are based on the following passage.
Imagine a society in which cash no longer exists. Instead "cash" is electronic, as in bankcard systems. Currency and coin are abandoned. The immediate benefits would be profound and fundamental. Theft of cash would become impossible. Bank robberies and cash-register robberies would simply cease to occur. Attacks on shopkeepers, taxi drivers, and cashiers would all end. Purse snatchings would become a thing of the past. Urban streets would become safer. Retail shops in once-dangerous areas could operate in safety. Security costs and insurance rates would fall. Property values would rise. Neighborhoods would improve.
Drug traffickers and their clients, burglars and receivers of stolen property, arsonists for hire, and bribe-takers would no longer have the advantage of using untraceable currency. Electronic "money" would leave incriminating wails of data, resulting in more arrests and convictions. These prosecutions, in turn, would inhibit further crimes.
The impact of the monetary change on underground economies would be nearly as dramatic as the effect on crime. In the United States, the underground economy is estimated at between 10% and 28% of the gross national product. Internal Revenue Service (IRS) researches suggest that almost all hidden labor is paid in currency.
In a society devoid of physical money, a change from cash to recorded electronic money would be accompanied by a flow of previously unpaid income-tax revenues running in the tens of billions of dollars. As a result, income-tax rates could be lowered and the national debt reduced.
Cash has been the root of much social and economic evil. The emergence of electronic funds-transfer technology makes it possible to change the nature of money and to divorce it from evil. Eighty percent of Americans regularly use credit cards. The development of a federal system to handle the country’ s 300 billion annual cash transactions in the United States electronically is within reach.
A national electronic-money system would operate as debit-card system. Each individual’s "money" would be held in his money-system account. A transaction would effect an instant transfer of "money" from his account to that of another account holder.
The principal differences between a national electronic-money system and commercial bank-card systems would be: the money system would be federally operated; payment would constitute "legal tender"; system-account holders would be able to receive as well as pay out funds by use of their accounts; and funds would be transferable between private-account holders as well as between merchants and private-account holders.
Only cash would be supplanted by electronic money. The use of checks, drafts, money orders, traveler’s checks, cashier’s checks, as well as letters of credit, acceptances, and other financial instruments would remain in regular use. Credit card and automatic-teller-machine systems (ATMs) would not necessarily change, although you could no longer obtain cash at ATMs.

According to the author, we must change ______.

A.the forms of the money in order to catch thieves and robbers

B.the nature of money in order to root out the cause of evils

C.the availability of money so that evils can be stopped

D.the use of money so that income-tax can be reduced

答案

参考答案:B

单项选择题
填空题

Ⅰ.在一定体积的密闭容器中,进行如下化学反应:其化学平衡常数K与温度t的关系如下:CO2(g)+H2(g) CO(g)+H2O(g),其化学平衡常数K和温度t的关系如下表:

t(℃)70080083010001200
K0.60.91.01.72.6
请回答下列问题:

(1)该反应为           反应(填“吸热”或“放热”)。

(2)800℃,固定容器的密闭容器中,放入混合物,其始浓度为c(CO) =" 0.01" mol/L,c(H2O) =" 0.03" mol/L,c(CO2) =" 0.01" mol/L,c(H2) =" 0.05" mol/L,则反应开始时,H2O的消耗速率比生成速率      __       _(填“大”、“小”或“不能确定”)。

Ⅱ.超音速飞机在平流层飞行时,尾气中的NO会破坏臭氧层。科学家正在研究催化技术将尾气中的NO和CO转变成CO2和N2,其反应为:2NO+2CO2CO2+N2。为了测定在某种催化剂作用下的反应速率,在某温度下用气体传感器测得不同时间的NO和CO浓度如表:

时间(s)012345
c(NO)

(mol/L)

1.00×1034.50×1042.50×1041.50×1041.00×1041.00×104
c(CO)

(mol/L)

3.60×1033.05×1032.85×1032.75×1032.70×1032.70×103
请回答下列问题(均不考虑温度变化对催化剂催化效率的影响):

(1)在上述条件下反应能够自发进行,则反应的△H       0(填写“>”、“<”、“=”)。

(2)前2s内的平均反应速率v(N2)=                

(3)在该温度下,反应的平衡常数K=              

(4)假设在密闭容器中发生上述反应,达到平衡时下列措施能提高NO转化率的是       

A.选用更有效的催化剂                                 B.升高反应体系的温度

C.降低反应体系的温度                                 D.缩小容器的体积

(5)若在恒温、恒压条件下向平衡体系中通入氩气,则平衡          移动(填“向左”“向右”或“不”);使用催化剂,上述反应的△H________(填“增大” “减小” 或“不改变”)。