exo-
comb form 构词成分 external, outside or beyond 外部的; 外面的; 外
exoskeleton / ˈeksəuskelɪtn; ˌɛkso`skɛlətn/, ie external covering on an animal, eg the shell of a crab
exogamous / ekˈsɔgəməs; ɛks`ɑɡəməs/, ie marrying outside one's religion, caste, etc.