在数据库系统中,用户所见的数据模式为________。
A.概念模式
B.外模式
C.内模式
D.物理模式
参考答案:B
When most people refer to multimedia, they generally mean the combination of two or more continuous media, usually with some user (115) . In practice, the two media are normally audio and video, this is, (116) plus moving (117) . It should be’ obvious by now that transmitting multimedia material in uncompressed form is completely out of (118) . The only hope is that massive compression is possible. Fortunately, a large body of research over the past few decades has led to many compression techniques and algorithms that make multimedia transmission (119) .
A.display
B.games
C.help
D.interaction
E.pictures
F.sound
G.web