“f1”

We have one entry that includes the term f1.

F1 layer

noun

: the lower of the two layers into which the F region of the ionosphere splits in the daytime that occurs at varying heights from about 80 to 120 miles (130 to 200 kilometers) above the earth's surface

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  • any of a genus helianthus especially h annuus of new world composite plants with large yellow rayed flower heads bearing edible seeds that yield an edible oil
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