string(263) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=cpi%E4%B8%8Eppi%E7%9A%84%E5%8C%BA%E5%88%AB%E4%B8%8E%E8%81%94%E7%B3%BB%E4%B8%8E%E4%BA%8B%E4%BE%8B => Failed to connect to 101.91.112.32 port 38195: Connection refused"
cpi与ppi的区别与联系与事例
