第三十期答案如下
1-20 cabbc baaca ccbca babcb
21-40 cdbdb bcadd bcdcc cadbb
41-60 cdaba cbdac acdbd bcddc
61-75 badad ccdab cbadc
76.of变为from 77.absorbing变为absorbed
78.over变为to 79.up变为dowm
80.去掉from 81.picture变为pictures
82.up后加with 83.it后加that
84.get变为take 85.frozen变为freezing