string(231) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=%E6%8A%95%E8%B5%84%E5%9B%9E%E6%8A%A5%E7%8E%87%E5%92%8B%E7%AE%97 => Failed to connect to 101.89.117.144 port 38017: Connection refused"
投资回报率咋算
