【单选题】设R和S分别为r和s元(度)关系,且R有n个元组,S有m个元组。执行关系R和S的笛卡儿积,记作T=R×S,则( )。
【多选题】苏轼在赋的创作上也是宋代的佼佼者,他的( )都是流传千古的代表作。
【单选题】These books are _____ written for those who learn how to use computer. It’s an ABC of computer l
A.
70. These books are _____ written for those who learn how to use computer. It’s an ABC of computer learning. A.particularly
【单选题】Learning to use a computer is getting easier all the time because
A.
programs are becoming less complicated
B.
programs are designed to be convenient to users
C.
programming is becoming easier and easier
D.
programs are becoming readily available to computer users
【简答题】两概念的外延只有部分重合,即有S是P,有S不是P;有P是S,有P不是S。这是 A包含关系 B属种关系 C交叉关系 D.对立关系
【多选题】苏轼在赋的创作上也是宋代的佼佼者,他的()都是流传千古的代表作。
【多选题】苏轼在赋的创作上也是宋代的佼佼者,他的( ) 都是流传千古的代表作。
【单选题】设R和S分别为r和s元(度)关系,且R有n个元组,S有m个元组。执行关系R和S的笛卡儿积,记作:T=R×S,则下列叙述中正确的是
【单选题】R和S分别为r和s元(度)关系,且R有n个元组,S有m个元组。执行关系R和S的笛卡儿积,记作:T=R×S,则下列叙述中正确的是