I would say that in the long run probably Communist China is likely to be in more of an expansionist phase than Soviet Russia...In their tactics, the Chinese Communists are probably the greater menace;

Challenges are opportunities in disguise; embrace them with courage.

物理定律是普遍的，但我们对它们的理解在不断演变。

The concept of polynomial-time reduction is central to understanding the structure of NP-complete problems.