string(257) "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%E7%9A%84%E5%8D%95%E4%BD%8D%E5%92%8C%E6%8D%A2%E7%AE%97%E5%85%B3%E7%B3%BB => Failed to connect to 101.89.120.29 port 38104: Connection refused"
带宽的单位和换算关系
