A farmer invited engineers, physicists and mathematicians to enclose the largest area with the fewest fences. The engineer enclosed a circle with the fence and declared it to be the optimal design. The physicist pulled the fence into a line A long straight line, assuming that the fence is infinitely long, I think it would be big enough to surround half the earth. The mathematician mocked them well. He surrounded himself with very few fences, and then said, "I am now in outside. ". What doesn't the truth illustrate in this story include? ['Farmers and scientists.', 'Be good at thinking from multiple perspectives.', 'Questioning, imagination is the ladder of human progress.', 'If you want to be innovative, you must constantly adjust your thinking.']