make a face
This example builds a simple yellow face from SVG primitives: a circle for the head, black circles for eyes, an arc path for the mouth, and rectangles for eyebrows. The left eyebrow animates upward and back down using chained `transition().duration()` calls on its `y` attribute. Code uses D3 v5’s `select`, `arc`, and `attr` methods to position elements within a 960×500 SVG. The animation runs once on load, with no data source.