string(276) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=%E6%8A%95%E5%85%A5%E4%BA%A7%E5%87%BA%E6%AF%94%E5%9C%A8%E5%A4%9A%E5%B0%91%E6%98%AF%E5%90%88%E7%90%86%E7%9A%84 => Failed to connect to 101.89.117.144 port 38056: Connection refused"
投入产出比在多少是合理的
