单选题
Americans are proud of their variety and individuality, yet they love and respect few things more than a uniform, whether it is the (21) of an elevator operator or the uniform of a five-star general. Why are uniforms so (22) in the United States? Among the arguments (23) uniforms, one of which is that in the eyes of most people they look more (24) than civilian clothes. People have become conditioned to expect (25) quality from a man who wears a uniform. The television repairman who wears a uniform (26) to inspire more trust than one who appears in (27) clothes. Uniforms also have many practical benefits. They save on other clothes. They (28) on laundry bills. Uniforms also give (29) to some practical problems. Though they are long lasting, often their initial expense is (30) than the cost of civilian clothes. Some uniforms are also expensive to maintain, requiring professional dry cleaning rather than the home laundering possible with many types of civilian clothes.