[单项选择]使用麻醉药品的医务人员必须具有________以上专业技术职务，并经考核能正确使用麻醉药品。（）
A. 医师
B. 主治医师
C. 副主任医师
D. 主任医师

The combined sales of the 100 largest foreign investing companies in the U. S. increased by a 40% in the two years between 1977 and 1979, and the number has continued to increase steadily. In 1980 South Africa proved to be the largest financial investor in the U. S. controlling about $19. 2 billion in sales. The Netherlands and the U. K. follow as second largest investors--and Germany next. New to the list of the top 100 foreign investors are 12 banking and finance and insurance companies--the largest, the Hong Kong Shanghai Banking Corp. , from Hong Kong. The number of Latin American companies engaged in business here is growing steadily, often through third country holding companies.
Why are so many firms coming to the U. S. There are many reasons. One of the greatest attractions, of course, is a market of over 200 million consumers with a high average per capital income. In addition, with the devalued dollar the cost of American labor has declined significantly, relati
A. the environment is politically stable
B. the market in the U.S. is very attractive
C. the labor cost there has been reduced
D. the U. S. technology is advanced