This is the 1470th most frequent French word.
chacune
Each one.
In this sentence, 'chacune' is used as a pronoun referring to each individual flower within the specified group 'des fleurs du jardin'.
Chacune des fleurs du jardin est soigneusement arrosée.
Each of the flowers in the garden is carefully watered.
Here, 'chacune' functions as a pronoun replacing 'elle' for emphasizing the individuality of actions taken by each member of the plural subject 'elles'.
Elles ont reçu des cadeaux ; chacune a exprimé sa gratitude.
They received gifts; each one expressed her gratitude.
In this example, 'chacune' highlights that the action 'présenter leur travail' was done individually by every member of the group 'les étudiantes'.