4Facione,P.A.Critical Thinking:A Statement of Expert Consen sus for Purposes of Educational Assessment and Instruction (The Delphi Report)[M].The California Academic Press, 1990.
5Kelman, S.American Government [M].New York : Holt, Rinehart and Winston, 1999: 21.
6Kelman, S.Ameriean Government [M].New York : Holt, Rinehart and Winston, 1999.
7Boorstin,D.J.Breoks Mather Kelley:A History of the U nited States[M]. Prentice-Hall,Inc., 1999.
8Wilhelm, J.D.Glencoe American Literature [M].Columbus : The McGraw-Hill Companies, Inc., 2009.
9Biggs, A., Kapicka, C., &Lundgren, L.Biology : The Dynamics of Life [M].New York : The McGraw-Hill Companies, Inc., 1998.