A gravel covered plain is called a Reg. A reg is a desert basin where the sand has been blown away leaving a gravel covered plain.
Answer:Nonrenewable energy resources, like coal, nuclear, oil, and natural gas, are available in limited supplies. This is usually due to the long time it takes for them to be replenished.
Renewable resources are replenished naturally and over relatively short periods of time.
Explanation:
The answer is C. Rubber. Iquitos profited greatly from the boom of the rubber industry, beginning in the 1900s.
"The Silurian is a geologic period and system spanning 24.6 million years from the end of the Ordovician Period, at 443.8 million years ago, to the beginning of the Devonian Period, 419.2 Mya.<span> <span>Wikipedia."
https://www.google.com/search?q=He+Silurian+period+occurred&rlz=1C1RUCY_enUS760US760&oq=He+Silurian+...
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