Transportation and communication networks bring people together. Yet sometimes people themselves create barriers to transportation and communication. In some countries, laws stop people from moving freely from place to place.
Over the centuries, many groups of people have been denied the freedom to travel because of their race, religion, or nationality. In the Middle Ages, for example, Jews were often forbidden to move about freely within certain cities. South Africa's government used to require black Africans to carry passes when they travel within the country. Some governments require all citizens to carry identification papers and to report to government officials whenever they move.
Countries set up Customs posts at their borders. Foreign travellers must go through a Customs inspection before they are allowed to travel in the country. Usually travellers have to carry special papers such as passports and visas(签证). Some countries even limit the number of visitors to their country each year. Others allow tourists to visit only certain areas of the country, or they may require that travellers be with an official guide at all times during their stay.
Many of those barriers to travel also act as barriers to communication. When two governments disagree with each other on important matters, they usually do not want their citizens to exchange news or ideas freely. Countries often try to keep military or industrial information secret.
Today, people have the ability to travel, to communicate, and to transport goods more quickly and easily than ever before. Natural barriers that were difficult or dangerous to cross a hundred years ago can now be crossed easily. The barriers that people themselves make are not so easy to overcome. But in spite of all the different kinds of barriers, people continue to enjoy travel and the exchange of goods and ideas.
小题1:The examples in paragraph 2 are used to tell the readers that _______
A．Customs posts are necessary at the borders of the countries
B．people have been allowed to travel freely within the country
C．people have not been permitted to travel freely for various reasons
D．travellers have to carry special papers such as passports and visas小题2:Some governments limit the freedom of communication because___
A．they think such freedom will lead to wars
B．they more often than not agree with each other on important matters
C．they intend to keep their national secrets unknown to others
D．they want to show their authority over communication小题3:We may learn from the passage that _______
A．people do not care about the removal of barriers between countries.
B．people can not remove the obstacles made by themselves
C．barriers should be taken for granted as they always exist
D．man-made barriers are sometimes harder to overcome than natural ones小题4:Which of the following can serve as the best title of the passage?
A．Functions of Communication
B．Barriers Made by People
C．Restrictions on Transportation
D．Progress of Human Society
小题1:C
小题2:C
小题3:D
小题4:B
题目分析：随着科技的发展，人们的交流越来越多，但是人们会制造出各种各样的人为障碍阻碍人际交流。自然的障碍容易解决，但是人为障碍难以逾越。
小题1:细节题：文章第二段第一句为主题句Over the centuries, many groups of people have been denied the freedom to travel because of their race, religion, or nationality.，然后举例说明由于种族、宗教、国籍等多种原因，有些人的行动自由受到限制。选C。
小题2:细节题：根据文章第四段的描述Countries often try to keep military or industrial information secret.
，有些政府限制通讯自由是为了保守国家机密。选C。
小题3:归纳题：从文章最后一段The barriers that people themselves make are not so easy to overcome.可概括出其段落主题为：人为障碍难以逾越。选D。
小题4:主旨题：通读全文，主要围绕人为障碍阻碍人际交流这一话题展开，所以选B项。