如果我们想保护森林,就必须先了解它们。
让来的来,让去的去。找出剩下的是什么。
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.