性關係

sexual relations / sexual contact / intercourse

nature / character / property / quality / attribute / sexuality / sex / gender / suffix forming adjective from verb / suffix forming noun from adjective, corresponding to -ness or -ity / essence / CL:個|个[ge4]

mountain pass / to close; to shut; to turn off / to confine; to lock (sb) up; to shut (sb in a room, a bird in a cage etc) / to concern; to involve

relation / relationship / to concern / to affect / to have to do with / guanxi / CL:個|个[ge4]

to connect / to relate to / to tie up / to bind / to be (literary)