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【简答题】
简述什么是数据库的三级模式结构和两级映像。
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举一反三
【简答题】These are different types of buses (range) ______ from 11 seats to 44 seats.
【简答题】A．at the back of the plane. B．in aisle seats. C．in window seats. D．near to the toilets.
【单选题】Passengers sitting ____________ are required to be over 18 years old and read the safety instruction card very carefully.A. in the window seats B. in the aisle seats C. next to the emer...
A.
in the window seats
B.
in the aisle seats
C.
next to the emergency exits
D.
in the middle seats
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