4. A. 细节题。 利用问题句中的特征词（US police forces）， 细节信息结构（pop songs）及被选项中的共有词criminals共同作为答案线索， 在文章中查找答案相关句：
If there is one group of Workers across the Western world who wm be glad that Christmas is over that group is shop workers．
    It is not that they like to complain．They realize that they are going to be rushed off their feet at Christmas．They know that their employers need happy customers to make their profits that pay their wages．But there is one thing about working in a Shop over Christmas that is too bad to tolerate．
    That thing is music．These days，au Shops and many offices have what is known as “Piped music1” or “muzak” playing for au the hours that they are open．Muzak has an odd history． During the 1940s，music was played to cows as part of a scientific experiment．It was found that COWS which listened to simple，happy music produced more milk．Perhaps workers and customers who  listened to simple， happy music would be more productive and spend more money.
    In fact，nobody knows what effect playing muzak in shops has on profits．It is simply something that everybody does．But we are learning more about the effect of constantly repeated hearings of songs on the people who have to hear them all the time．
    （第3题答案相关句）Research shows that repeated hearings of complex pieces of music bring greater enjoyment before becoming tiresome．And that point come mach sooner with simple songs2.
    “That’s especially the case with tunes that arc already familiar one that tipping point3 is reached，repeated listening become unpleasant，says professor John Sloboda of UK’s Keele University’s music psychology group．“And the less control you have over what you hear, the less you like it”
  （第7段）That′s why police forces in the US often try and resolve(解决， 决心)  hostage（人质） situations by playing（播放） pop songs over and over again （反复地）at high volume． Eventually（最后）, it becomes（变得） too（太...而不能...） much for the criminals to stand（站立，忍受） and they give up（放弃）． 
答案相关句说：在人质被劫持的情况下，美国警察常常对罪犯用大音量播放流行歌曲，  目的是让罪犯最终难以承受而放弃劫持。
 
5.According to （根据）the article（文章），which of the following （下列哪项）most appropriately （最恰当地）indicates（显示，指出） the nature（自然， 本质） of the effect（影响）repeated hearing of the same tune（曲调） produces（产生， 引起） on the hearer（听者， 听众）?
  A)Social（社会的， 社交的）．
  B)Physical（物理的， 身体的）．
  C)Psychological（心理的）．
  D)Both physical and psychological． 
5．D． 细节题。 利用被选项中的修饰结构（social, physical, psychological）共同作为答案线索， 在文章中查找答案相关句：
If there is one group of Workers across the Western world who wm be glad that Christmas is over that group is shop workers．
    It is not that they like to complain．They realize that they are going to be rushed off their feet at Christmas．They know that their employers need happy customers to make their profits that pay their wages．But there is one thing about working in a Shop over Christmas that is too bad to tolerate．
    That thing is music．These days，au Shops and many offices have what is known as “Piped music1” or “muzak” playing for au the hours that they are open．Muzak has an odd history． During the 1940s，music was played to cows as part of a scientific experiment．It was found that COWS which listened to simple，happy music produced more milk．Perhaps workers and customers who  listened to simple， happy music would be more productive and spend more money.
    In fact，nobody knows what effect playing muzak in shops has on profits．It is simply something that everybody does．But we are learning more about the effect of constantly repeated hearings of songs on the people who have to hear them all the time．
    Research shows that repeated hearings of complex pieces of music bring greater enjoyment before becoming tiresome．And that point come mach sooner with simple songs2.
    “That’s especially the case with tunes that arc already familiar one that tipping point3 is reached，repeated listening become unpleasant，says professor John Sloboda of UK’s Keele University’s music psychology group．“And the less control you have over what you hear, the less you like it”
  （第4题答案相关句） That′s why police forces in the US often try and resolve hostage situations by playing pop songs over and over again at high volume．Eventually, it becomes too mach for the criminals to stand and they give up．
    The problem gets particularly bad at Christmas，when the muzak consists entirely of the same few festive tunes played over and over again. What makes it worse for the shop workers is that they already know these tunes．They get bored very quickly．Then they get irritated．Then they get angry．
    Shop workers in Austria recently threatened to go on strike for the right to silence．“Shop workers can’t escape the Christmas muzak. they feel as if they are terrorized all day．Especially ‵Jingle Bells4.It arouses aggressive feelings，”said Gottfried Rieser, of the Austrian shop worker′s union．
    It is not just shop workers who complain．A survey this year by UK recruitment website Retailchoice.com found that Christmas is not only the most testing time for shop workers，but that almost half had complaints from customers about muzak．And the British Royal National Institute for the Deaf estimates that some stores play jingle Bells 300 times each year
    “That’s acoustic（有关声音的） torture（折磨， 痛苦），”says Nigel Rodgers of Pipedown，a group against（反对） muzak.″It′s not loud(高声的) but the repetitive（重复的） nature（本质）causes （造成）psychological stress（压力）．” 
    The group wants the government（政府） to legislate against （立法反对）unwanted（不必要的，讨厌的） music in stores, hospitals， airports，swimming pools and other public places， claiming（声称， 主张） it raises（提高， 饲养，募集） the blood pressure (血压) and depresses(压低，使沮丧/) the immune（免疫的） system 
    Perhaps groups like Pipedown don’t really have much to complain about．After all，surely the real point is that people have money to spend．Why complain about a bit of music?
根据答案相关句的内容判断：反复听同一个曲调对听者产生的影响有心理方面的，也有生理方面的。