【单选题】【消耗次数：1】
使用二维表格结构表达实体及实体间联系的数据模型是（ ）
①
层次模型
②
网状模型
③
关系模型
④
联系模型
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用二维表来表示实体及实体之间联系的数据模型称为[填空]。
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being greatly reduced
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greatly to reduce
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TOEFL is a test for students __________ native language is not English.
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that
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__________ all our efforts to save the school, the authorities decided to close it.
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①
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②
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③
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④
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①
Oh, how are you
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I’m John
③
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I don’t want to go
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③
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④
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