【单选题】It is helpful to illustrate these points by looking at the case of the United States, precisely because 3.__________. Coal, copper, iron, silver, and nickel are just a few of the natural resources the...
A.
countries need to - or choose to import at least some goods and services
B.
different countries have comparative advantages on different products
C.
exports are also more than just an outlet for “ excess ” production
D.
it has the capability of producing the goods or supplying the services
E.
it comes closer to being self-sufficient than most other countries
F.
sell goods or services to other countries at prices higher than the prices
【简答题】For millions of years, the ________ of South-east Asia, South America and Africa have been the Earth's natural chemical laboratories, plant gardens, and zoos.