one theory, a theory / another theory, a different theory

passage (in a book or a poem)

he / distal demonstrative, something far off removed from both speaker and listener: that / boyfriend

distal demonstrative, something far off removed from both speaker and listener: that, yon / particularly, male personal third person pronoun: he / by extension from he: boyfriend

he; boyfriend

kill two birds with one stone, do one task and finish two or more goals (literally, “one stone, two birds”)

a lifetime, one's whole life

a short period of time / being completed in a short period of time, easily, overnight

一石二鳥: “one stone, two birds” → kill two birds with one stone: do one task and finish two or more goals

to depart / be detached from common sense