This example demonstrates basic SVG shape primitives rendered with D3.js in a React environment. It displays rectangles, circles, ellipses, and lines with static styling, showcasing fundamental SVG element creation. The code uses D3 version 4 selections to append shapes directly to an SVG canvas, loading data from a CSV file for positioning. A second version uses `d3.scaleLinear` and `d3.interpolateBlues` to map data values to circle radii and fill colors, with mouseover and mouseout events controlling opacity to highlight individual circles.