根据短文内容，选择最佳答案。    Cats are animals that live on land. They can be divided into two groups: big cats and small cats. Big cats are the larger animal species. Here are some materials about big cats.

	Tigers are one of the largest cats. They live in the forests and marsh areas of South-East Asia, India, Russia and Southern China. Tigers mostly live alone and mainly hunt at night. Young tigers leave their mothers at about two years of age.
	Lions live mostly on the larger grassland of Africa. Unlike tigers, lions are the most social of the big cats. They live in family groups and hunt together. There can be up to 35 lions in a group. They use speed and strength to catch and kill their prey.
	Leopards live mostly in the forest on the edges of plains in Africa and Asia. New born leopards only open their eyes after 10 days. They spend much of the day resting in trees. They do most of their hunting at night. They eat almost any animal they can catch.