Final answer:
In English, the words 'fast' and 'rapid' are used interchangeably to describe something that happens quickly, with 'fast' emphasizing physical speed and 'rapid' emphasizing a quick process or change.
Step-by-step explanation:
In English, the words 'fast' and 'rapid' are often used interchangeably to describe something that happens quickly. For example, you could say 'He ran fast to catch the bus' or 'The car accelerated rapidly.' Both words convey the idea of speed. However, there is a subtle difference in connotation. 'Fast' is more commonly used to describe physical speed, while 'rapid' can describe a quick process or change. For instance, you could say 'She solved the math problem fast' or 'The technology industry is experiencing rapid growth.' In both cases, the words emphasize the speed of an action or event.
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