string(284) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=%E5%B8%A6%E5%AE%BD%E5%92%8C%E9%80%9F%E7%8E%87%E7%9A%84%E5%85%B3%E7%B3%BB%E5%85%AC%E5%BC%8F%E6%98%AF%E4%BB%80%E4%B9%88 => Failed to connect to 101.89.120.29 port 38231: Connection refused"
带宽和速率的关系公式是什么
