2. Einstein used the mathematical formula of "A=x+y+z" to prompt the secret of success: "A stands for success, X stands for hard work, Y stands for the correct method, and Z stands for less empty talk." Edison's: "Genius = 1% inspiration +99% sweat." In the famous sayings of these two great scientists, _ _ _ _ _ _ _ _ is the same, that is to say, in order to succeed, you must _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.

3. a: the latter. Because he said: "A person is like a score, his practical ability is like a numerator, and his evaluation of himself is like a denominator. The larger the denominator, the smaller the score. "

4. Only when a person has more knowledge will he find that he knows more, as the saying goes, there is no limit to learning.