string(238) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=usb3.0%E4%BC%A0%E8%BE%93%E9%80%9F%E5%BA%A630m%E6%AD%A3%E5%B8%B8%E5%90%97 => Failed to connect to 61.171.74.35 port 38027: Connection refused"
usb3.0传输速度30m正常吗
