A、He didn’t like physics any more. B、His eyesight was too poor. C、Physics was too hard for him. D、He had to work to support hims

When I was at school, my ambition was to be a pilot in the Air Force. But my eyesight wasn’t good enough. So I had to give up the idea. I went to university and studied physics. I wanted to stay on there and do research, but my father died at about that time. So I thought I’d better get a job and earn my living. I started working in an engineering firm.
  I expected to stay in that job for a long time. But then, they appointed a new managing director. I didn’t get on with him, so I resigned and applied for a job with another engineering company. I would certainly have accepted the job if they had offered it to me, but on my way to the interview I met a friend who was working for a travel agency. He offered me a job in Spain. And I’ve always liked Spain, so I took it.
  I worked in the travel agency for two years and then they wanted to send me to South America. But I had just got married. So I decided to stay here. Then we had a baby and I wasn’t earning enough to support the family. So I started giving English lessons at a school in the evening.
I liked the English teaching more than working for the travel agency, and then the owner of the school offered me a full-time job as a teacher. So I resigned from the agency. Two years later, the owner of the school wanted to retire, so he asked me to take over as the director. And here I am.