试述股骨头骨软骨炎病理及X线表现？
参考答案：
股骨头骨软骨炎病理及X线表现：①第一期（渗出期）：关节中滑膜肿胀、充血、关节渗出、骨质疏松外无明显变化。关节肿胀、骨质疏松、脱钙、关节间隙增宽，髋臼泪滴与股骨头之间距离增宽尤为明显。②第二期（坏死期）：骨骺有大片点状坏死区域，细胞致密，核溶解，骨小梁断裂，骨骺腔充满坏死骨组织与渣滓，不见骨质炎症或吸收。股骨头密度加深，骨骺出现扁平。③第三期（潜行替代期）：骨片开始吸收，新生的血管、肉芽进入，坏死骨片消失，出现结缔组织，有大量血管、红细胞、淋巴细胞、早期骨组织生长。骨骺全部扁平，分裂成小块，股骨颈下有骨质吸收区域。④第四期（残余期）：骨片吸收完成，残留坏死骨质极少，新生骨大量出现，吸收坏死骨质，再生完成，形成扁平髋、髋臼覆盖不良以及髋臼硬化等。骨骺逐渐生长、增厚、密度减退、恢复正常，但常出现股骨头扁平、蕈状畸形、股骨头向外移位。
Passage Two
| During the last thirty years, the international economy has experienced a basic change. Improvements in the Internet and other communications have had important effects on world markets. Faster methods of transport from one place to another have made the world seem smaller to the businessmen. As a result, the world no longer. consists of a number of separate economies under the control of different nations. Instead, the nations have been integrated into a single economy, and the integration is becoming more and more complete every year. For the first time in history, we can truly speak of a global economy. The most dramatic example of this integration was the oil crisis of 1973 and 1974. It came as a great surprise to the public in the industrial nations to discover that they depended so heavily on imported oil. However, the best evidence for the growing integration is the rapid expansion in the volume of world trade. It went up by about 7% a year during the decade from 1990 to 2000, and in several quasi-industrial (半工业的) countries the growth was even more rapid. As a result, some imported products have become as common as domestic commodity. Some of them are too common for the public to any more realize they are foreign. Production has also become international, which is manifested by the large corporations stepping across national borders and established branches and subsidiaries in several different countries. As an example, U.S. companies are building automobiles in Canada, Germany, Britain and Japan. In some cases, components of an automobile are produced abroad and shipped to the United States, where it is then finished with the imported parts. When even the United States has the largest number of such corporations, it is not the only. Other multinationals, for instance, are based in Japan, France, Germany, the UK and Italy. Labor, too, is much more mobile than in the past. Both skilled and unskilled workers can now readily migrate from one country to another. In Europe, for example, there are large numbers of Turkish workers employed in the Germany Economy. Doctors, lawyers, and other professionals are also finding it easier to work in foreign countries. The labor market has become international, and the number of expatriate workers is continuing to grow. |
The most convincing indication that we are bordering on a global economy is ______ .
A．faster methods of transport
B．the establishment of more multinational corporations
C．the oil crisis of 1973 and 1974
D．the growth of international trade