Puzzle 20

Painters of walls.

University students routinely buy them for courses.

Slowest standard swimming stroke.

Host of a TV show.

Spherical winter souvenir bought in cold countries.

Illuminator invented by Thomas Edison.

State of focusing on feelings, may include crying.

Marvin Gaye heard it through the __.

Thumb a lift.

Muscle exercises to combat sedentary periods.

Proverbially, it's the mother of invention.