不成熟的诗人模仿；成熟的诗人偷窃。

The effects of policy changes are often more nuanced than simple economic models suggest.

Over the centuries the Indians developed sign language for communicating phenomena of interest. Programmers from different tribes (FORTRAN, LISP, ALGOL, SNOBOL, etc.) could use one that doesn't require them to carry a blackboard on their ponies.