21~30 CBBDA ACBCB
31~40 ADBAB DBACB
41~50 DADBC ADBAC
51~55 DBADC
56.needn`t have watered
57.what he is like
58.can win back the medal
59.whichever you are interested in
60.should/ought to have cleaned
61.will have been finished
62.to look forward to
63.can`t have written
64.what makes me excited
65.how tirde he was