WHAT IS THE MAIN IDEA OF THE ARTICLE
36.What is the main idea of the article?
A.Zoos are now places to preserve animals and to display them in their natural
surroundings.
B.Zoos are places where people can see animals from all over the world.
C.A modem zoo has many cages with bars.
D.Some zoos have special places for visitors to watch animals that live under water.