The security dilemma is a fundamental feature of international politics, as states' efforts to increase their own security often decrease the security of others.

I'm the one who makes me happy.

你将要学到的最伟大的事情就是去爱，并被爱回报。

旅行的用途是用现实来调节想象力，而不是想象事情可能是怎样的，而是看到它们实际是怎样的。