You should answer these questions yourself. Here is the lesson link - easily discoverable with a site search. 

https://kwiziq.learnfrenchwithalexa.com/revision/grammar/questions-quel-quels-quelle-quelles-which-what

J'ai vu que la règle n'est pas tout à fait claire pour moi, et pour le niveau élémentaire d'apprentissage des langues, il m'est difficile de comprendre la grammaire

The lesson is at A2 level. If you are beginning, it is better to follow the lessons starting from A0 level. There is little point in just getting the answers. The reason the answers are what they are is what needs to be understood and that information is certainly covered progressively through the levels. Where did the questions come from? They don't look like they are from this site.

These questions were sent by my teachers at the school, and I do not know their answers

I guess you have to talk to your teachers at your school, then.