【单选题】在关系模式R(U,F)中,如果X→Y,YÍ X,则称函数依赖X→Y为( )。
【单选题】—Have you thought of the topic for the composition? — Not yet.I _____ it very carefully, but I haven’t decided.
【单选题】听力原文:M: Where have you been? I thought I was going to have to take the plane without you. W: I'm sorry, I thought we were going to meet in front of the check-in. Fortunately I thought of coming to the...
A.
On the railway platform.
B.
Near the departure gate.
C.
In front of the check-in.
【单选题】在关系模式R(U,F)中。如果X→Y,如果不存在X的真子集X1,使X1→Y成立,则函数依赖X→Y为
【单选题】西方一些学者根据公司管理结构的演变及其在国外销售额增长情况,将处于不同发展阶段的企业分为【 】
【简答题】The teacher __________ have thought Johnson was worth it or she wouldn’t have wasted time on him, I suppose. A.should B.can C.would D.must