Formanyyears,peopleelectricears.However,makingthemhasbeenmoredifficultthanpredicted.()A.haddreamedofB.havedreamedofC.dreamedofD.dreamof
For many years,people __ electric ears.However,making them has been more difficult than predicted.( )
A. had dreamed of
B. have dreamed of
C. dreamed of
D. dream of
For many years,people __ electric ears.However,making them has been more difficult than predicted.( )
A. had dreamed of
B. have dreamed of
C. dreamed of
D. dream of
已知地球半径为R,地球自转周期为T,同步卫星离地面的高度为H,万有引力恒量为G,则同步卫星绕地球运 2020-04-12 …
(35)设关系 R,S 和T 分别如下图所示。则有T A)T= R ? S B)T= R ? SC) 2020-05-23 …
关系模式R(C,T,H,R,S),有如下函数依赖集:F={C→T,(H,R)→C,(H,T)→R,( 2020-05-24 …
关系模式R(C,T,H,R,S),有如下函数依赖集: F={C→T,(H,R)→C,(H,T)→R, 2020-05-24 …
有关系模式A(C,T,H,R,s),根据语义有如下函数依赖集:F={C→T,(H,R)→C,(H,T 2020-05-24 …
______ A.(S,C)B.(T,R)C.(T,P)D.(T,S)A.B.C.D. 2020-05-26 …
纵横字谜之英语暑假作业题(s)(o)(r)(r)(n)(g)(r)(e))(a)(k)(k)(e) 2020-06-06 …
“大”字下面一个“面”是什么字?大字下面一个巴呢?已经查清:奤夿屯Hǎbātún〖Habatun〗 2020-06-12 …
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给出一棵树的逻辑结构T=(K,R),其中K={A,B,C,D,E,F,G,H,I,J}R={r}r 2020-07-22 …