States are inherently aggressive and expansionist because they exist in an anarchic international system where there is no higher authority to keep them in check.

他们的服饰不同，他们的行为确是一样的。 

A good abstraction is one that emphasizes the important details and suppresses the unimportant ones.

"A good book is an event in my life."

文章贵在简洁，简洁则明了；贵在疏朗，疏朗则通畅；贵在深远，深远则持久。