题目

What makes a person a scientist? Does he have ways or tools of learning that are different from those of others? The answer is “no”. It is not the tools a scientist uses but how he uses these tools that makes him a scientist. You will probably agree that knowing how to use a power is important to a carpenter. You will probably agree, too, that knowing how to investigate(调查),how to discover information, is important to everyone. The scientist, however, goes one step further, he must be sure that he has a reasonable answer to his questions and that his answer can be confirmed by other pe修一段公路，已修的和未修的比为5：4，已修了这段公路的________．