用待定系数法求微分方程y"-y=xex的一个特解时，特解的形式是(式中α、b是常数)
A. (αx2+bx)ex
B. (αx2+b)ex
C. αx2ex
D. (αx+b)ex
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Mrs. Smith ______ .
A. thought she would have plenty of time to see the sights
B. was afraid they would have no time to travel around New York
C. thought the hotel was not good as small inn
Mrs. Brown took good care of the vegetables in her back garden.
A. Right.
B. Wrong.
C. Doesn't say.
According to the passage, which of the following statements is NOT true about Rowling？
A. She is unsentimental.
B. She is skillful in twisting plots.
C. She is good at subtle characterizations.
D. She is gifted with describing things unreal.
Which of the following leads to Blair's failure in office？
A. The war in Iraq.
B. His ideas in foreign policy.
C. His close relationship with George Bush.
D. His good intention to help the Iraqi peopl
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