One day, I received a call from a colleague. He was about to give a student a zero for his answer to a physical problem ,while the student claimed a perfect score. I was elected as their arbiter( ).I read the examination problem: "Show how it is possible to determine the height of a tall building with the aid of a barometer ." The student had answered: "Take the barometer to the top of the building,attach a long rope to it,lower it to the street,and then bring it up, measuring the length of the rope. The length of it is the height of the building. " The student had really answered the question completely ,but the answer didn't confirm his competence in physics. I suggested the student try again. I gave him six minutes to answer the question, warning that the answer should show some knowledge of physics. Five minutes later, he said he had many answers and clashed off one, which read: "Take the barometer to the top of the building and lean over the edge of the roof. Drop the barometer, timing its fall with a stopwatch. Then, use the physical formula  to calculate the height of the building. " At this point, my colleague had to accept it, and then the student made almost full marks. I couldn't help asking the student what the other answers were. He listed many others ,and then added5"Probably the best is to take the barometer to the. administrator and said to him,' Sir, here is a fine barometer. If you tell me the height of the building, I will give it to you.," Then, I asked the student if he really did not know the conventional answer to this question. He admitted that he did ,but said that he was fed up with high school and college instructors trying to teach him how to think. The name of the student was Bohr who later was famous all over ,the world. He won the Nobel Prize for Physics in 1922. The student got a zero at the beginning because  _  .
the teacher wasn't satisfied with him his answer wasn't complete or correct the teacher clicln 5t fully understand his answer his answer didn't show his knowledge of physics