D
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, poor land must be cultivated and good land made full use of. Thus, each person produces less and this means a lower average income than could be obtained with a smaller population. Other economists have argued that a large population gives more opportunities for specialization such as ports, roads, and railways, which are not likely to be built unless there is a big demand to justify them.
One of the difficulties in carrying out a world-wide birth control program lies in the fact that official attitudes to population growth vary from country to country depending on the level of industrial development and the availability of food and raw materials. In a developing country where a vast expanding population is pressing hard upon the limits of food, space and natural resources, it will be the first concern of the government to place a limit on the birthrate, whatever the consequences may be. In a highly industrialized society the problem may be more complex. A decreasing birthrate may lead to unemployment because it results in a declining market for products. When the pressure of the population on housing declines, prices also decline and the building industry is weakened. Faced with considerations such as these, the government of a developed country may well prefer to see a slowly increasing population, rather than one which is stable or in decline.
54．According to the first paragraph, a smaller population may mean______ if land is limited.
A．lower productivity, and a lower average income
B．lower productivity, but a higher average income
C．higher productivity, and a higher average income
D．higher productivity, but a lower average income
55．In a developed country, people will perhaps go out of work if the birthrate_______.
A．goes up B．goes down  C．remains stable  D．is limited
56．It is not easy to carry out a worldwide birth-control program because______.
A．there are too many underdeveloped countries in the world
B．developing countries are short of food and raw materials
C．even developed countries may have some complex problems of population
D．different governments show quite opposite views to the population