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【单选题】
在关系模型的完整性约束中，实体完整性规则是指关系中__（1）__，而参照完整性（即引用完整性）规则要求__（2）__。空白（2）处（）A.
不允许引用不存在的
B.
允许引用不存在的
C.
不允许引用不存在的属性
D.
允许引用不存在的属性
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【简答题】在△ABC中,∠B=60°,2AB=3BC,则tanA的值等于( ). (A)-22. (B)-32. (C)32. (D)±32.
【单选题】It is reported that the scientists in our country are ______ all possible ways to control H1N1 f
A.
32. It is reported that the scientists in our country are ______ all possible ways to control H1N1 flu. A．operating
B.
designing
C.
replacing
D.
Exploring
【简答题】 a reply to an order
【简答题】A．She doesn't want a reply. B．She'll send a reply by mail. C．She prefers the man to reply by phone. D．She doesn't know the man's phone number.
【简答题】Reply to counter-offer
【单选题】____ will be appreciated.
A.
You reply our letter early
B.
You reply to our letter early
C.
Your early reply our letter
D.
Your early reply to our letter
【单选题】We are waiting ______ your reply ______ our letter.
A.
----， of
B.
for， to
C.
---- of
D.
---，----A35
【简答题】______ reply, we offer firm, subject ______ your reply reaching us on or before Sept．30 for 250 metric tons of Groundnuts, Handpicked, Shelled and Ungraded ______ RMB 2 000 net per metric ton CFR Cope...
【简答题】Reply to a counter-offer
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