Animals have been kept as pets by people in all parts of the world for thousands of years.

The most【C1】______pets are dogs, cats, birds and fish. But many people【C2】______unusual pets,【C3】______snakes, crocodiles and monkeys. Many Japanese children【C4】______mice and teach【C5】______to dance【C6】______music. The people of India【C7】______pets of snakes.

Pets can make interesting, playful【C8】______. People enjoy teaching them to do【C9】______and to【C10】______commands. Pets owners often【C11】______their pet to be a member of the family. Many children spend more time with their pets than they do with adults.【C12】______. caring for pets, children learn responsibility. They must【C13】______that their pets have food, ex excise, and a proper place to live in. Most children like【C14】______to and even telling secrets to their pets.

Pets also can【C15】______to a person's general well-being. Research shows that【C16】______with animals can improve a person's morale, and that the presence of pets can lower【C17】______blood pressure. Many people look and feel more relaxed【C18】______with their pets. Many people living【C19】______in nursing homes or in hospitals enjoy community programs that bring pets to visit. Today, many such institutions keep cats, birds, fish and other pets for their【C20】______.

【C1】

A．ordinary

B．familiar

C．usual

D．common