human-generatedCOCA¹²⁶³¹³ 例句 Researchers are still working to quantify the precise percentage of natural versus human-generated PM2.5, but it's clear that both types contribute to the hotspots that show up in the new map. 学者们正在精确的定量人为的和自然产生的 PM的比例，但很明确这两种共同为地图上的热点做出贡献，一起呈现在地图上。 www.tcalliance.org.cn