多项选择题
Which of the following is mentioned by Shannon in the original 1948 paper " A mathematical theory of communication" ? A、Discrete noiseless systems B、The discrete channel with noise C、mathematical preliminaries D、The continuous channel
单项选择题 ---Did you watch the basketball match on TV last night? ----I wanted to, but my father ______his favourite TV program. A. watched B. was watching C. watches D. is watching
单项选择题 A、 B、 C、 D、
单项选择题 DNS域名服务器体系中具有（ ）台根服务器，其中1台主根域名服务器放置在（ ）。 A、13，美国 B、14，英国 C、11，中国 D、10，日本
