题目

已知点A（﹣4，﹣5），B（6，﹣1），则以线段AB为直径的圆的方程为 ． 答案：【答案】（x﹣1）2+（y+3）2=29．【解析】试题由中点坐标公式得线段的中点坐标为，即圆心的坐标为；，故所求圆的方程为：．故答案为：．（贵州省兴义九中09-10学年高三上学期期中考试） D Most nations today, regardless of their degree of economic development or their political philosophies, recognize the importance of marketing. Indeed, economic growth in developing nations depends greatly on the ability to design effective marketing systems for their raw materials and industrial output. Today, a global marketplace is forming. In many (perhaps most) national markets, companies from numerous countries compete fiercely. Consider the U.S. market, for instance. Until the late 1970s, the United States provided a large domestic(国内的) market for American firms, and there was no significant foreign competition in most industries in that market. But the picture changed dramatically through the 1980s as foreign firms improved their products and their marketing knowledge, and then successfully entered the American market. Many imported products have achieved large sales: office equipment, autos, watches, semiconductors, and consumer electronics, for example. As a result the United States has been running large annual trade deficits (赤字), meaning that imports greatly exceed exports. In the early 1980s, the competition facing U.S. firms came primarily from Japanese companies. Later, companies in the four "Asian tigers" (Korea, Taiwan, Singapore, and Hong Kong added to competitive pressures. In the 1990s, continuing competition from these Pacific Rim countries and regions will be augmented (增强) by a new challenge from Western Europe. Starting in 1992, the 12-nation European community will remove internal(内部的) trade barriers and adopt uniform technical, financial, and marketing standards. A more integrated European Community will open major marketing opportunities for internationally minded U.S. firms, but at the same time, it is expected to intensify(激化) competition. More and more American firms, many large ones and even some rather small ones, are moving into foreign markets. Many companies are concluding that achieving profit is most likely through a combination of domestic and international marketing rather than only reliance on domestic marketing. 68. According to the first paragraph, we know that            . A. the developing nations are more concerned with economic development than the developed ones B. marketing is important to the developing nations only C. both the developing nations and the developed ones are aware of the marketing D. politics plays a major role in economy 69. The author provides an example of the United States in Paragraph 3 in order to         .     A. show that the United States was a highly potential market     B. show the fierce competition brought on by the global market     C. show that the United States was quite successful in marketing     D. explain how to face market competition effectively 70. The last paragraph tells us that              .     A. most American firms are unwilling to enter foreign markets     B. a nation will achieve better economic profit by relying on its home market     C. international marketing is more important than domestic marketing     D. international marketing and domestic marketing should be given equal attention 71. It can be concluded from the passage that            .     A. market competition becomes fierce as a global market comes into being     B. the United States suffered little from foreign market competition     C. Japanese companies were the most powerful competitors of the U. S in the 1990s D. European Community has virtually removed all differences among themselves as a result of their new policy in 1992