听力原文： Like most other folk art, the calendar pictures were not considered to be art in their own day. People just thought of them as a way of decorating a practical object. In fact, the calendar pictures were originally printed as advertising for various companies that made hunting or fishing products, like guns or fishing rods. The calendars were handed out free to the customers to thank them for the business.
Most people just hung the calendars on their walls with the pictures faded in the sun and then tore the pictures off the calendar as each month passed. As a result, collectors today place a lot of value on the calendars that are complete and in good condition.
Even though the people who used the calendars didn't regard them as art, the original paintings were often of good quality. In fact, many famous wild life painters created calendar art at some point in their lives. To them it was a way of getting their work reproduced and shown around. One interesting thing is the way these pictures reflect changing attitudes towards wild life. The pictures often portray the adventure of hunting rather than any particular concern for wild life preservation, But most of today's wild life art shows animals in their natural surroundings without any humans in the scene. This modern wild life art appeals to a large number of the nature lovers, even those who are opposed to the practice of hunting.
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A. Very few were produced.
B. Most were kept only a short time.
C. Most were pointed on delicate paper.
D. Many have been acquired by collectors.