听力原文： We must admit that their job is not the most romantic one in the world. We often take dustmen for granted. Perhaps because they usually come very early in the morning, before most people are up, we are inclined to forget that they exist. Our dustbins are emptied regularly, but we rarely stop to think about the men who do this. However, it is one of the most important jobs in the world, and when there are no dustmen to take away the rubbish the general public soon becomes aware that something is wrong.
Recently, the dustmen of England went on strike for higher wages. During the first few days it was regarded as a joke. For some reason, jokes have always been made about dustmen, and some people thought this strike was very amusing. But when the first two weeks had passed, and the dustbins were overflowing in nearly every backyard in the country, the joke did not seem so funny any more. As the strike continued, people could not bear the accumulation of rubbish around their dustbins, and they looked for other places in which to get rid of it. Even when the strike was over, and the wages dispute had been settled, it took several weeks for the country to get cleaned up completely, as so much rubbish bad accumulated. Perhaps now the English people appreciate the work of their dustmen rather more highly, and won't take them for granted any more.
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A. Because they are often early risers.
Because they often do their work unnoticed.
C. Because they were born to do their work.
D. Because people never stop to talk to them.