請依下文回答第 57 題至第 60 題 There is perhaps no single substance so vital to life yet so often taken for granted in modern timesas salt. Throughout history, salt has played pivotal roles in human health as an agent of both nutritionand food preservation. Salt is so important, in fact, that in the past access to it could determine thesuccess or failure of a population. Many of the earliest cities were founded and thrived specifically dueto their proximity to a natural salt source. The ancient world was made up of regions where salt was abundant and others where it was not;therefore, salt was one of the original motivators for trade. Given the weight of the commodity, it wasmost easily transported by boat. Evidence has been uncovered of a Mayan salt production center inGuatemala located next to a principal riverine trading route. The marine salt trade in the Mediterraneanregion is well documented, and Marco Polo noted during his visit to China that salt was shipped fromthe coast up the Yangtze River in great quantities. The high value of salt provided great power to those who controlled its distribution, and many ofhistory’s great cities owed their affluence to it. Venice, for example, gained prominence partly as a resultof the salt gathered in its lagoons. By 1350, Venice had secured a monopoly, and all salt produced in theAdriatic region had to pass through Venice, where its price was marked up substantially before it couldbe sold. The wealth derived from this trade helped fuel the artistic and scientific innovations of theItalian Renaissance. The role salt has played throughout history is impressive. Columbus’s voyage ofdiscovery to the New World was financed by salt production in Southern Spain. France’s territorialexpansions under Napoleon were largely paid for by a tax charged on salt purchases, and the State ofNew York used a similar tax to fund the creation of its 363-mile Erie Canal.
57 What is the passage mainly about?
(A)The value of naturally occurring salt today
(B)The decrease of our need for salt over time
(C)Salt’s impact on civilizations throughout history
(D)The possible uses of salt in the future