a b c c c\bc,abcd,acd,d,abcde,1,2对3，4错
A,D,A,A,D
1.D 2.C 3.C 4.A 5.A1.ABCE 2.ABCDE 3.ABCDE 4.AD 5.ABCE 1.错 2.对 3.对 4.错
