填空题 When people feel sick, doctors treat them. So, who treats animals? Veterinarians are{{U}} (1) {{/U}}. But they also protect human health. Veterinarians are{{U}} (2) {{/U}}against animal diseases that{{U}} (3) {{/U}}. Diseases, like some kinds of bird flu, can spread to humans. Others, like{{U}} (4) {{/U}}, cause economic damage. Some veterinarians in the United States{{U}} (5) {{/U}}. Some study diseases. Others work for drug companies and medical companies. And about half of all veterinarians care for more than one-hundred-million cats and dogs that{{U}} (6) {{/U}}. Becoming a veterinarian is hard work. Students take two years of{{U}} (7) {{/U}}. They must learn in the classroom about animal biology, diseases, {{U}}(8) {{/U}}. Then, they attend four years in a college of veterinary medicine. There, students work in laboratories and treatment centers to{{U}} (9) {{/U}}about animal health. They also learn to{{U}} (10) {{/U}}. There are twenty-eight schools of veterinary medicine in the United States. {{U}}(11) {{/U}}study the subjects. Seventy-five percent of the students are women. About two-thousand new veterinarians{{U}} (12) {{/U}}each year. States give veterinarians{{U}} (13) {{/U}}to treat animals. A veterinarian must take a test to receive a license{{U}} (14) {{/U}}where he or she works. A number of groups help veterinarians. The American Veterinary Medical Association is one of the oldest. It started in eighteen-eighty-nine. The organization{{U}} (15) {{/U}}that teach veterinary science. The{{U}} (16) {{/U}}established the National Veterinary Accreditation Program in 1921. The program was designed to teach veterinarians how to work with{{U}} (17) {{/U}}supervising animals raised for food. The program gives veterinarians{{U}} (18) {{/U}}. Veterinarians have always been important to{{U}} (19) {{/U}}. They set broken bones, {{U}}(20) {{/U}}, perform operations and help animals give birth. Many also are involved in the study of diseases that spread among animals.