单项选择题：在linux系统中，修改组的id号使用的命令是（）。A、chmod B、usermod

题型：单项选择题

My parents operated a small restaurant in Seattle. It was open twenty-four hours a day, six days a week. And my first real job，when I was six years old，was小题1:the diners’ shoes. My father had done it when he was young，so he taught me小题2:to do it efficiently，telling me to 小题3:to Re-shine the shoes if the customer wasn’t小题4:.

Working in the restaurant was a cause of great小题5:because I was also working for the good of the family. But my father小题6:that I had to meet certain standards to be part of the team. I小题7:to be punctual，hard-working，and polite to the小题8:.

I was小题9:paid for the work I did at the restaurant. One day I made the mistake of advising Dad that he小题10:give me $10 a week. He said，“OK. How about you paying me for three meals a day you have here? And小题11:the times you bring in your friends for free soft drinks?” He小题12:I owed him about $40 a week.

I remember returning to Seattle after being小题13:in the US Army for about two years. I had just been promoted to Captain at that time. And full of pride，I walked into my parents’ restaurant，but the小题14:thing Dad said was，“How about your小题15:up tonight?” I couldn’t小题16:my ears! I am an officer in the Army! But it didn’t 小题17:as far as Dad was concerned，I was just 小题18:member of the team. I reached for the mop. Working for Dad has taught me the devotion to a小题19:is above all. It has nothing to do with小题20: that team is involved in a family restaurant or the US Army.

小题21:A．cleaning shining C．removing D．keeping