【单选题】【消耗次数：1】
设有关系模式R(S，D，M，A,T)，其函数依赖集：F＝{S→D，D→M, A→T }，则关系模式最高满足（ ）。
①
A.1NF
②
B.2NF
③
C.3NF
④
D.BCNF
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【多选题】
设有关系模式R(A，B，C，D)，其数据依赖集：F＝{(A，B)→C，C→D}，则关系模式R不满足（ ）。
①
A.1NF
②
B.2NF
③
C.3NF
④
D.BCNF
【多选题】
设有关系模式R(A，B，C，D)，其数据依赖集：F＝{(A，B)→C，C→D}，那么(A，B)→C是________
①
平凡函数依赖
②
非平凡函数依赖
③
部分函数依赖
④
完全函数依赖
【简答题】
有关系模式R(U,F)∈1NF，U=（A,B,C），若(A,B)→C，B→C，则该关系模式的规范化程度为[填空1]NF。
【单选题】
有关系模式R（U,F）∈1NF，若R中任意的非平凡的函数依赖X→Y，X中均包含码，则关系模式R的规范化程度至少为( )。
①
A．2NF
②
B．3NF
③
C．4NF
④
D．BCNF
【单选题】
已知关系模式R(A，B，C，D，E)及其上的函数依赖集合F＝{A→D，B→C，E→A}，该关系模式的候选码是（ ）。
①
A.AB
②
B.BE
③
C.CD
④
D.DE
随机题目
【单选题】
Hitler was wrong and we should ______ to help Russia.
①
go out all@go all out
②
make out all
③
make all out
【单选题】
This is no time to moralize ______ the follies of countries which have allowed themselves to be struck down one by one.
①
to
②
on
③
by
④
in
【单选题】
Hitler was however wrong and we should ______ to help Russia.
①
make all out
②
make out all
③
go all out
④
go out all
【单选题】
In June 1941 Hitler suddenly ______ an attack on Russia.
①
launched
②
exerted
③
developed
④
created
【单选题】
He said that everyone should turn their backs _____ a craving for fame and prestige.
①
for
②
down
③
up
④
on
【单选题】
The subjugation of the western Hemisphere______ his will…
①
to
②
in
③
according to
④
against
【单选题】
We shall ______ all our friends and allies in every part of the world to take the same course and pursue it.
①
appeal to
②
appeal for
③
appeal with
④
appeal of
【单选题】
He gambled ______ being able to buy a ticket at the last minute.
①
about
②
on
③
in
④
with
【单选题】
The big shot ______ several government officials in the past years.
①
buy out
②
buy up
③
buy off
④
buy down
【单选题】
Please ______ you cigar before entering this building.
①
put down
②
put up
③
put off
④
put out