A simple animated face demonstrates basic D3.js shapes and transitions. Four circles and several arc paths create eyes, eyebrows, and a smile over a dark green background. The left eye, smile, and both eyebrows move vertically using chained `transition().duration()` calls, while the right eye remains static. The code uses d3.arc() to generate path data and SVG element selection with d3.select(). No external data source is used; all shapes are manually positioned within a 960x500 SVG canvas.