Increasingly, the development of tourism is seen to have an effect on the environment. Erosion (磨损) is one problem. The steps and stones of major popular (51) like Shakespeare’s birthplace or Stonehenge (巨石阵) are literally being worn away by millions of foreign feet. The (52) in the case of Britain’s best known prehistoric monument has been to use railings to keep visitors at a distance. Such measures can hardly be (53) in the house of the Bard, however, where tourists want to enter the actual building.
Overcrowding in cities, towns and villages is (54) problem. Traffic jams are an outcome. In narrow roads, tourist vehicles cause congestion. (55) traders and residents cannot get around to do their work. Car parks fill up, (56) strangers park their cars where they can: in streets, across gateways, in lay-bys, or even in (57) driveways. This causes obstruction. The sheer weights of in-comers can be a hazard. Thus Venice, a city built for half a million inhabitants, is (58) by another half million who populate the city daily in the tourist (59) —eight million visits each year. The mayor recently decided to (60) visitors to 90,000 a day. the only way to save the city from overcrowding.
56().
A.because
B.yet
C.so
D.or
参考答案：C
解析：
上一句指出，“停车场爆满”，此句相关部分的意思是“陌生人把车停在能停车的任何地方。”上下文之间表达的是一种因果关系，所以正确答案应为C项so“因此、所以”。A项because填入空格处会使上下文之间的因果关系颠倒；B项yet“然而；但是”表示转折关系；D项or表示选择，都不符合上下文的意思。