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Answer:
Formaldehyde can be added as a preservative to food, but it can also be produced as the result of cooking and smoking. Formaldehyde also occurs naturally in the environment. Humans and most other living organisms make small amounts as part of normal metabolic processes. Formaldehyde is also a byproduct of combustion. When burning natural gas, kerosene, gasoline, wood, or tobacco, formaldehyde is produced. Automobile exhaust is a common source of formaldehyde in our environment. Tobacco smoking in the home is another source of the chemical in the indoor environment.
Explanation:
“ The rebels promised to provide laborers to help the United States build Panama Canal. “
The important contribution to navigation made by Eratosthenes in the third-century bc was a reasonably accurate calculation of the circumference of our planet.
Who is Eratosthenes?
Eratosthenes was born in 276 BC and died in 194 BC. He was a well-known poet, mathematician, a researcher in geography, and theorist of music. He was the first to gauge the size of the planet.
The Earth was first measured by Eratosthenes of Cyrene. The precise measurement of Earth's circumference was greatly aided by Eratosthenes' work in the third-century bc.
As a result, the Eratosthenes in the third century bc accurate calculation of the Earth.
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