Well what you are trying to say were all of the ancient African governments successful, and in order to give a more specific answer the question has to be slightly more specific.

yes

Weight loss programs are successful if you follow the specific guidelines. As long as it's a healthy way to lose weight it should be a successful program. The hardest part is sticking with it.

There is no specific enviroment.It must live in a enviroment where its predators are scarce.

This cannot be answered, without knowing what specific person you are asking about.