Let's make a face with D3.js!
A smiling face is drawn with D3.js v5, using simple SVG shapes like circles and rectangles for the head, eyes, and brows, with a path for the mouth. The entire face is centered via a group transform, and the eyebrows animate by moving down and up repeatedly using chained `transition` calls with a two-second duration. The example demonstrates basic D3 selection, shape construction, and animation through the `select` and `arc` APIs.