deux petits exercices que je n’ai pas trop compris (je suis nulle aidez moi)

Bonjour
Voici l'exercice 4
Explications :
a) Slaves were transported in boats.
b) An exhibition will be proposed on the heritage of slaves.
c) Slavery was abolished over 150 years ago.
d) The gaspel is inspired by the songs of the slaves.
Bonne journée ;)