when animals or humans do things naturally, without learning, they do it by ____
when there are so few examples of a kind of animal or plant that it might die out completely, it is ___
The year an organization such as the London Zoological Society was started or established is the date it ___
Some zoos have a ___ with lists of endangered animals.
To change so as to be able to live or work in new conditions is to _____.