概念模型既可以向关系模型转换，也可以像层次模型或网状模型转换。
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How much is the monthly income of Michael's monthly budget?
A. 1,595 dollar
B. 605 dollar
C. 2,200 dollar
D. 2,500 dollar
Michael spends more than he gets each month.
A. 对
B. 错
The money from Michael's parents is enough to pay for his rent and groceries.
A. 对
B. 错
Rent is the major expense for Michael each month.
A. 对
B. 错
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