最近Youtube、Twitter、Facebook不能访问，可以通过修改Hosts的方法来实现访问：
file:///C:/Windows/System32/drivers/etc，打开host文件，在最后加入以下内容
203.208.39.104 www.youtube.com
203.208.33.100 gdata.youtube.com
203.208.39.99 upload.youtube.com
128.121.146.228 twitter.com
128.121.146.228 www.twitter.com
128.121.146.101 assets0.twitter.com
128.121.146.101 assets1.twitter.com
128.121.146.101 static.twitter.com
128.121.146.229 assets2.twitter.com
128.121.146.229 assets3.twitter.com
65.74.185.41 twitter.zendesk.com
65.74.185.41 help.twitter.com
69.63.180.173 login.facebook.com
69.192.34.110 s-static.ak.facebook.com
69.63.176.69 secure-profile.facebook.com
69.63.176.59 secure-media-sf2p.facebook.com
69.63.178.13 ssl.facebook.com
96.6.122.57 profile.ak.facebook.com
64.211.21.152 b.static.ak.facebook.com
file:///C:/Windows/System32/drivers/etc，打开host文件，在最后加入以下内容
203.208.39.104 www.youtube.com
203.208.33.100 gdata.youtube.com
203.208.39.99 upload.youtube.com
128.121.146.228 twitter.com
128.121.146.228 www.twitter.com
128.121.146.101 assets0.twitter.com
128.121.146.101 assets1.twitter.com
128.121.146.101 static.twitter.com
128.121.146.229 assets2.twitter.com
128.121.146.229 assets3.twitter.com
65.74.185.41 twitter.zendesk.com
65.74.185.41 help.twitter.com
69.63.180.173 login.facebook.com
69.192.34.110 s-static.ak.facebook.com
69.63.176.69 secure-profile.facebook.com
69.63.176.59 secure-media-sf2p.facebook.com
69.63.178.13 ssl.facebook.com
96.6.122.57 profile.ak.facebook.com
64.211.21.152 b.static.ak.facebook.com