21. DBACC 26. DBABD 31. CDAAA 36. CCADA

　　41. BCACB 46. BBDCB 51. BBBAB 56. BBBCA 61. BDCDA 66. BCDBB

　　71. CDBBD 76. ACBBD 81. ACACC 86. BAACC