My father is an engineer. He works very hard.
    Once I asked my father what the secret of success was. He didn't say a word，but wrote a few words on a piece of paper and handed it to me. I looked at the paper，it was written：A=X+Y+Z.
    “What does it mean？”I asked.
    “A means success，”explained my father. “X means hard，Y means good ways，and Z means you must stop talking and start to work.”
    That's right. From then on，I tried my best to be better.