string(252) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=roi%E8%AE%A1%E7%AE%97%E5%85%AC%E5%BC%8F%E4%B8%AD%E6%8A%95%E8%B5%84%E6%80%BB%E9%A2%9D => Failed to connect to 125.88.227.171 port 38062: Connection refused"
roi计算公式中投资总额
