How can the reader tell that "Digital Cameras" is a scientific text?

I don't know what article you're talking about but it think that scientific texts have to have facts in the writing.

the article " digital cameras" is a scientific text because it explains how digital cameras work.

answer: the tobacco industry has traditionally been one of the most important industries in north carolina and a backbone of the state's agricultural heritage. yet as the north carolina economy continues to transition from an agricultural economy to a manufacturing and, increasingly, service-based economy, the industry faces new challenges, both at home and abroad

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