下面的短文有15处空白，请根据短文内容为每处空白确定1个最佳选项。 A Country’s Standard of Living The "standard of living" of any country means the average person’s share of the goods and services the country produces. A country’s standard of living, (51) , depends on its capacity to produce wealth. "Wealth" (52) this sense is not money, for we do not live on money (53) on things that money can buy: "goods" such as food and clothing, and "services" such as transport and entertainment. A country’s capacity to produce wealth depends upon many factors, most of (54) have an effect on one another. Wealth depends (55) a great extent upon a country’s natural resources. Some regions of the world are well supplied with coal and minerals, and have fertile (肥沃的) soil and a favorable climate; other regions possess none of them. Next to natural resources (56) the ability to turn them to use. China is perhaps as well-off (57) the USA in natural resources, but suffered for many years from civil and external wars, and. (58) this and other reasons was (59) to develop her resources. Sound and stable political conditions, and (60) from foreign invasions, enable a country to develop its natural resources peacefully and steadily, and to produce more wealth than another country equally well favoured by nature but less well ordered. A country’s standard of living does not only depend upon the wealth that is produced and consumed. (61) its own borders, but also upon what is directly produced through international trade. (62) , Britain’s wealth in foodstuffs and other agricultural products would be much less if she had to depend only on (63) grown at home. Trade makes it possible for her surplus (过剩的) manufactured goods to be traded abroad for the agricultural products that would. (64) be lacking. A country’s wealth is, therefore, much (65) by its manufacturing capacity, provided (如果) that other countries can be found ready to accept its manufactures.