choices.label: A B C D
choices.text: guangdong:guangxi:guangdong and guangxi ocean:island:sea island shanghai:nanjing:shanghai-nanjing expressway technology:ethics:science and technology ethics
explanation: both "hong kong" and "macao" are special administrative regions, and "hong kong and macao" is the collective name for the former two. "guangdong" and "guangxi" are both provinces, and "guangdong and guangxi" are the collective names of the former two. "islands" are land scattered in the "ocean", and "sea island" is not the general term for the former two. "shanghai" and "nanjing" are both cities, but "shanghai-nanjing expressway" is not a general term for the former two. "science and technology" and "ethics" have different categories. "science and technology ethics" is a kind of "ethics", which is the ideology and code of conduct for the relationship between man and society, man and nature, and man and man in scientific and technological innovation activities.
relation: hong kong macau R2.6
relation: guangdong guangxi R2.6
relation: ocean island R3.10
relation: shanghai nanjing R2.6
relation: ethics science and technology ethics R2.2