git - ubuntu apt-get update时报错！！在线等！急！急！急！！
［问题补充］
换用科大的源后报错：
PHP中文网2017-05-02 09:50:38
It is probably a network problem. Try changing the source. It seems that yours is the Tsinghua source. Try using the HKUST source instead. HKUST source
淡淡烟草味2017-05-02 09:50:38
The link has timed out. Connection timed out Unable to connect to aliyun.com． ． ． Please ping it.