通读下面的短文，掌握其大意。然后，从每小题的四个选择项中选出可填入相应空白处的最佳选项。 　　In the past, I always thought that being a teacher was an easy job. But I changed my __21__ when I became a part-time teacher. About four years ago, Richard asked me __22__ I could help teach his students how to make a website about themselves. 　　I __23__ because computer is what I do well and I didn ’ t think teaching computer would be that __24_. 　　But when I taught Richard ’ s class，some of the students __25__ with their friends while I was explaining how to do something. At first I just got angry with them, __26__ Richard taught me to think why they were doing this. He said that if he was __27__ a lesson and the students were not listening ,then he was angry with __28__ for not making the lesson clear or interesting for them. I told him that I didn ’ t __29__ his idea. He then asked me if I had ever __30__ the same thing. That made me stop. Of course I had! 　　If any of my past teachers are __31__ this, I want to say sorry if I sometimes played around in the class __32__ you were teaching. I didn’ t think how that would make you feel. I promise I will do my best to be a good __33__ in the future. Please help us when we don’ t understand and most __34__，don, t be quick to be angry when we fail. __35__of us are perfect but with your help we can be successful.