Facebook has changed the way many people communicate - letting its millions of users share personal thoughts and images with their network of friends.

VOA: standard.2010.07.23

To know who its friends and enemies are?

辨别谁是友？谁是敌？

耶鲁公开课 - 政治哲学导论课程节选

To know who its friends and enemies are?

辨别谁是友？谁是敌？

耶鲁公开课 - 政治哲学导论课程节选