to use / to employ / to make use of, to apply / to spend

explanation

to explain

高言, 公言: boasting

公言: declare / 高言, 公言: boast

膠原質: collagen

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

江原道: Gangwon