Bonjour,

Réponse :

A person who campaigns for political changes = An activist ( un activist )

Expressing or communicating thoughts by speaking = A speech (un discours )

Somebody who is no more a kid … = A teenager ( un adolescent )

Withdraw from commercial or social relationship as a protest = Boycott

A refusal of work organised by employees as a form of protest = A strike

( une grève )

Showing a desire to resist authority …= Rebellious ( rebelle )

A public display of group feelings toward a cause, in the street = A

demonstration ( une manifestation )

Implication, actively participating in something =Involved in  ( impliqué dans.. )

Informing on a specific subject = Raise awareness ( sensibiliser )

;)