The advantages and disadvantages of a large population have long been a subject of discussion among economists. It has been argued that the supply of good land is limited. To feed a large population, inferior land must be (36)________ and the good land worked (37)________. Thus, each person produces less and this means a (38)________average income than could be obtained with a smaller population. Other economists have argued that a large population gives more (39) ________ for specialization and the development of (40) ________ such as ports, roads and railways, which are not likely to be built unless there is a big demand to (41) ________ them.
One of the difficulties in carrying out a (42) ________ birth control program lies in the fact that official attitudes to population growth (43) ________ from country to country depending on the level of industrial development and the availability of food and raw materials. In country where a vastly expanded population is pressing hard upon the limits of food, space and natural resources, (44)__________ , whatever the consequences may be. In a highly industrialized society the problem may be more complex. (45)___________________ . When the pressure of population on housing declines, prices also decline and the building industry is weakened. Faced with considerations such as these, (46)______________________, rather than one which is stable or in decline.
36.cultivated。所填词后面的and表示两句话，在结构上应该对称。The good land worked是一个省略了系动词的被动态，故所填词也应该是动词的过去分词形式，而且和inferior land构成动宾搭配。To feed a large population是目的，由此目的推导出的行为应该是“耕种土地”。
37.intensively。在这里，the good land worked intensively是指“要集中精力照料优质的土地，使其产量大幅提高”。这种措施和inferior land must be cultivated一样，都是为了feed a large population。
38.lower。Lower average income与produces less构成因果关系。
39.scope。Give scope for sth.为常用搭配，意为“使有机会做某事”。注意该空所在句子中的Other economists have argued that …表示下文要阐述与之前不同的观点。
40.facilities。所填词后面的such as表示列举，也就是说ports, roads and railways都属于所填词的范畴，而这些都是使交通便利的设施。
41.justify。所填词后面的them是指facilities，这句话的意思是“要不是有大量的需求证明这些设施是合理的，就”。这是Other economists的立场，即a large population的好处。
42.worldwide。所填词前面是不定冠词a，后面是名词词组，那么所填词一定是形容词，修饰birth control program(计划生育)。下文的from country to country， country和a highly industrialized society都暗示了birth control program是全世界范围的。
43.vary。该句中that引导的定语从句修饰fact，从句的主语是official attitudes to population growth，depending on …是状语，那么所填词一定作谓语。而且，所填词后面没有直接加名词作宾语，因此这里要填入一个不及物动词。“vary from …to …”是常用的搭配。
44.it will be the first concern of government to place a limit on the birthrate
【Main Points】government will be concerned to limit the birthrate first
45.A decreasing birthrate may lead to unemployment because it results in a declining market for manufactured goods
【Main Points】A decreasing birthrate may cause unemployment because market for manufactured goods is declining
46.the government of a may well prefer to see a slowly increasing population
【Main Points】a may prefer to see a slowly increasing population