题干

为了描述物体运动速度变化的快慢,在物理学中引入了加速度的概念。下列关于速度和加速度的说法中,正确的是()

A:物体的速度越大,加速度也越大

B:物体的速度为零,加速度也为零

C:物体的速度变化量越大,加速度越大

D:物体的速度变化越快,加速度越大

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D

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阅读理解

    The word advertising refers to any kind of public announcement that brings products and services to the attention of people. Throughout history, advertising has been an effective way to promote(促进)the trading and selling of goods. In the Middle Ages, merchants employed "town criers" to read public messages aloud to promote their goods. When printing was invented in the fifteenth century, pages of advertisements(ads)could be printed easily and were either hung in public places or put in books.

    By the end of the seventeenth century, when newspapers were beginning to be read by more people, printed materials became an important way to promote products and services. The London Gazette was the first newspaper to set aside a place just for advertising. This was so successful that by the end of the century several companies started businesses for the purpose of making newspaper ads for merchants.

    Advertising spread quickly throughout the eighteenth century. Ad writers were starting to pay more attention to the design of the ad text. Everything, from clothes to drinks, was promoted with clever methods such as repetition of the firm's name or product, words organized in eyecatching patterns, the use of pretty pictures and expressions easy to remember.

    Near the end of the nineteenth century, companies that were devoted to the production of ads came to be known as "advertising agencies(广告商)."The agencies developed new ways to get people to think of themselves as members of a group. Throughout the twentieth century, advertising agencies promoted consumerism(消费主义)as a way of life, spreading the belief that people could be happy only if they bought the "right" products.