估算在特定区域铺设期望深度的橡胶覆盖物所需的体积（立方英尺）和重量（磅）。
Rubber mulch is a type of ground cover made from recycled tires. It's known for its durability, excellent shock absorption (making it great for playgrounds), and ability to inhibit weed growth. Unlike wood mulch, it does not decompose over time. It's typically sold in bags by weight (lbs) or volume (cubic feet).