string(265) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=%E6%8D%A2%E6%89%8B%E7%8E%87%E5%A4%9A%E5%B0%91%E6%98%AF%E6%9C%80%E4%BD%B3%E4%B9%B0%E5%85%A5%E7%82%B9 => Failed to connect to 61.171.74.35 port 38041: Connection refused"
换手率多少是最佳买入点
