题目

My name is Sabrina. I’m 23 year old. I come from London. Now I live(生活) in Beijing. I love teaching  English . I think it’s interesting. I can speak Chinese, too. I have experience(经验) in teaching English in China. My e—mail address  is sabrina@sina.com. ————————————————————————— I’m Bill, an 18—year—old student. I live in Nanjing now. I can play the guitar well. I like to be a teacher. I have free time on weekends. Do you want to learn the guitar? Please call me at 15069606503. ————————————函数y=的导数为(  ) 　　A．　　　　　　　　  B． 　　D．　　　　　　　　　　　　   D．