According to the Declaration, when do people have a right to revolution? Why do they have this right?

They have the right to revolt when government doesn't protect or honor their natural right. Why? Because our natural rights were given to us by our Creator and cannot be taken away by government. John Locke states a lot about this topic.

france,russia and prussia had absolute monarchy and it meant:

when louis xiv inherited the throne, he was able to serve as his chief minister.louis xiv ruled as an absolute monarch.

i think it is true i hope this is