"Furrows" Natural Recordings by Native Speakers
Furrows are lines or grooves that are formed on the surface of something, especially the skin of the face or hands, caused by repeated motion or expression.
Furrowed is a verb that means to wrinkle or crease one's brow, typically indicating concern, worry, or concentration.
Furthered means increased or expanded in amount, scope, or effect; promoted or developed to a greater extent. It can also mean made more serious or severe.