但分离基于石油的可循环塑料和其他种类的塑料和固体废物十分困难、成本高昂且属于劳动密集型工作，因此只有少部分塑料得到了循环利用。
But the process of separating the petroleum-based recyclable plastics from other kinds of plastics and solid waste is difficult, costly, and labor-intensive, so only a small proportion is recycled.