Read text for question no. 30-34!

GORILLAS

    Gorillas are the largest of all the primates. A male gorilla can be 180 centimeters tall and can weigh 200 kilograms. Gorillas are very strong but they do not often fight. In fact they are peaceful animals. Gorillas live in small family groups of about 15. In a group there is one strong, older male, some young males, and a few females with their babies. They move slowly around a large area of jungle eating leaves and bushes.

    In some ways gorillas are very like humans. When they are happy, they laugh and wave their arms. When they are angry, they beat their chests. When they are sad, they cry. But they cry quietly, without any tears. Unfortunately, people hunt and kill gorillas. They also cut down and burn their trees. There are now only about 10,000 gorillas left in the world.

The main idea of the second paragraph is …