An old man walked slowly into a restaurant with his cane(拐杖).His old jacket and shoes made him unusual that day.

    A young waitress named Mary watched him move towards a table by the window.She ran over to him,and said with smile,“Here,sir.Let me give you a hand."

    Without saying a word,he gave her a smile. She pulled the chair out from the table and helped him sit down. Then she put his cane against the table where he could reach ithimself. In a soft, clear voice he said,"Thank you." "You're welome, sir," she replied. I'll be back in a moment, and if you need anything, just wave(挥手) at me!"

    After he had finished a good meal,Mary brought him the change. She handed him his cane, and walked to the front door. Holding the door open for him, she said,“Come back and see us, sir! ”The old man turned around and smiled.

    When Mary went to clean his table, she was shocked. Under the plate, she found a business card, a 100—dollar and a note.The note said.

    “Dear Mary, I respect you very much, and you respect yourself, too. It shows the way you treat others. You have found the secret of happiness."

    In fact,the old man was the owner of the restaurant. That was the first time that she, or any of his waitresses, had seen him.

如果一个式子与﹣3ab的积为﹣$\frac{3}{4}{a}^{2}bc$，求这个式子．

党的十八大之后，中央加大了惩治腐败的决心和力度，一批利用职务之便谋取私利的官员相继被查处，涉嫌违法犯罪的已受到法律的严惩。这表明（  ）
①法律是由国家制定或认可的                           ②法律对全体社会成员具有普遍约束力
③一切腐败行为都必将受到刑罚制裁               ④我国贯彻落实依法治国的基本方略