Making a face
A yellow circle with eyes, eyebrows, and a mouth forms a face using D3 v5 selections and SVG shapes. The right eyebrow animates upward and back down via chained `transition().attr()` calls over two seconds each, while the mouth is drawn with `d3.arc()`. All elements are positioned relative to a centered group, with eyes offset by fixed pixel distances, creating a simple, animated cartoon face.