Once there was something wrong with a machine in a factory. The workers could do nothing but turn to a German engineer for help, who drew a line on it and then said, "Take off the part where the line is and change it for a new one. "The machine, with a new line on, began running well again. The engineer then asked for $30,000 for what he had done. The following were what he wrote on a bill, "The new part only costs one dollar, and knowing where the problem with the machine is costs $29,999." One dollar for changing a new part sounds reasonable  but the $29,999 is exactly the value  of wisdom  and knowledge. The factory turned to the German engineer because   _  .
he had nothing to do in the factory there were no other people in the factory the workers could not repair the machine the workers asked for too much money for repairing the machine