题目

I used to be a very self-centered person, but in the past two years I have really changed. I have started to think about other people  16   I think about myself. I am happy that I am becoming a   17   person. I think my   18   started when I was at Palomar College. At first, I just wanted to get my   19   and be left alone. I thought I was smarter than everyone else, so I hardly ever  20    to anyone in my classes. By the end of my first semester, I was really   21   . It seemed as if everyone but me had made friends and was having fun. So tried a(n) 22   . I 有3辆客车，分别为50座、40座、48座，如有96人去植物园，乘(　　)座和(　　)座客车比较合适．