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D layer

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noun
the lowest region of the ionosphere, characterized by mounting electron and ion density: exists, during the day only, from about 43 to 50 miles (70 to 80 km) altitude.
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QUIZ YOURSELF ON "WAS" VS. "WERE"!
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“Was” is used for the indicative past tense of “to be,” and “were” is only used for the subjunctive past tense.
Compare D region.

Origin of D layer

First recorded in 1930–35

Words nearby D layer

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2022

How to use D layer in a sentence

Scientific definitions for D layer

D layer

See D region.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
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