CACBA,,CABAA,,BBCBA,,BCABC....CBACA,,,
CDDCD,,DBDAC,,,CDBAB,,DBCDA,,CABCD,,ADCBA,,CBD,,DCBC,,BCDA,,BAAD......BGACE....as改~when...去掉on....very改~too....it~which...insist~insisted....as后加a....so~but....regretted~regretting.....receive~accept.....were~was....
