Answer :
1) crayons - for this one they might be looking for multiple since it is using des as in multiple objects like crayons is saying more then one while crayon is only one and if you go along with the wording then I think crayons is the one that fits best since it is more then one object.
2) classe
3)dictionnaire
4)corbeille à papier
5) tableaux
2) classe
3)dictionnaire
4)corbeille à papier
5) tableaux