[单项选择]What is the reason of the nation’s lowest growth rate since the nineteen thirties
A. Only two states had the largest population increases.
B. The data was not true.
C. Falling birth rates among some groups and fewer immigrants because of the recession.
D. The population continues to move from the Northeast and Midwest to the South and West.

[填空题]The chief reason for the population growth isn’t so much a rise in birth rates as_______________________ (倒不如说由于医疗条件的改善而导致死亡率下降的缘故)

[填空题]The chief reason for the population growth is ______ (与其说是出生率的上升，还不如说是死亡率的下降).

[填空题]Nation trades with one another for two main reasons, to earn money and to enrich economy.

[简答题]The basic reason for the existence of multi-national companies is the competitive advantage of a global network of production and distribution. This competitive advantage arises in part from vertical and horizontal integration with foreign affiliates. By vertical integration, most MNCs can ensure their supply of foreign materials and intermediate products and avoid the imperfections often found in foreign markets. They can also provide better distribution and service networks. By horizontal integration through foreign affiliates, MNCs can better protect and exploit their monopoly power, adapt their products to local conditions and tastes, and ensure consistent product quality.