Let's make a face with D3.js!
This example builds a cartoon smiley face with animated eyebrows using D3.js. The SVG canvas is populated by selecting the root element and appending a group, then adding circles for the face, eyes, and a path for the mouth using the `arc()` generator. The code explicitly sets attributes like `r`, `cx`, `cy`, and `d` to position the shapes. The face appears centered, with the mouth drawn as a half-circle arc. The code relies on `d3.select` and `d3.arc` from the D3 v5 library, but no actual animation logic is present.