string(239) "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%A620%E5%85%86%E5%B7%A6%E5%8F%B3 => Failed to connect to 125.88.227.171 port 38062: Connection refused"
usb3.0传输速度20兆左右
