(weaponry) hydrogen bomb

involvement

be involved in, be engaged, enter the picture

bomb / (fishery jargon) bivalve shell that contains mud instead of flesh

development or exploitation of natural resources etc. / development or creation of new technology, drugs, or products / development or cultivation of talent or ability

to develop or exploit resources / to develop or create new products or fields / to cultivate talent or ability

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

hydrogen (chemical element) / hydrogen (molecular hydrogen)