A.7805 B.7915 C.7812 D.7912
A.低位由0變1時(shí) B.上一級(jí)由1變0時(shí) C.下一級(jí)由0變1時(shí) D.無(wú)規(guī)律
A.10001 B.10101 C.10111 D.10010