在数据库系统中,逻辑数据与物理数据有很大差别,这二者的相互转换是______的功能之一。
参考答案:实体集
Europe has achieved more in controlling the AIDS virus than Asia in the past ten years, ______ the
number of people infected with the virus is going up sharply. [ ]
A. when
B. which
C. that
D. where
国民待遇一般适用于外国公民和企业的经济权利。