1Maria Harper-Marinick,Engaging students in Problem-Based Learning[DB/OL] http://www.mcli.dist.maricopa.edu/fonum/spr01/mcliForumV1Sp01.pdf.(2005-02-15).
6Stevens,R.The Question as a Measure of Effciency in Instruction,Teachers' College Contributions to education[M].No.48,New York:Teachers'college Press,Columbia University.
7Perrott,E.Effective Teaching:a practical guide to improving yur teaching[M].London and New York:Longman,1982:41.
