A wooly underfur grows very thick in the fall and winter and keeps the wolf warm, while an outer layer of guard hairs repels snow and water, and keeps the underfur dry so it can trap air as an insulator.
(A wooly underfur; grows; very thick; L:in the fall and winter) (A wooly underfur; keeps; the wolf) (an outer layer of guard hairs; repels; snow and water) (A wooly underfur; keeps; the underfur) (it; can trap; air; as an insulator)
A wooly underfur A wooly underfur an outer layer of guard hairs A wooly underfur it
grows keeps repels keeps can trap
very thick L:in the fall and winter
the wolf
snow and water
the underfur
air as an insulator