A、 The merits and drawbacks of a large population.
B、 The disadvantages of a large population.
C、 The advantages of a small population.
D、 The rapidly growing world population.

【正确答案】 A

【答案解析】解析：短文首句说，“长久以来，人口众多的优势与劣势一直是经济学家们讨论的话题。”A中的merits对应文中的advantages。drawbacks对应disadvantages，故本题的答案为A。

A、 The level of education varies around the world.
B、 The economists' attitudes to population differ greatly.
C、 The living standard varies from country to country.
D、 The countries' attitudes to population differ greatly.

【正确答案】 D

【答案解析】解析：短文提到，“执行全球范围的计划生育困难之一在于，事实上每个国家对人口增长的官方态度都是不同的”。D表达的正是此义，故为答案。

A、 Great pressure on housing.
B、 Rising demands of goods.
C、 The prosperity of the building industry.
D、 A declining market for manufactured goods.

【正确答案】 D

【答案解析】解析：短文提到，“下降中的出生率可能导致失业，因为它会导致制成品市场衰退。”因此，本题选D。