精选优质文档-倾情为你奉上新概念二Lesson79课堂内容By airI used to travel by air a great deal when I was a boy. My parents used to live in South America and I used to fly there from Europe in the holidays. A flight attendant would take charge of me and I never had an unpleasant experience. I am used to travelling by air and only on one occasion have I ever felt frightened. After taking off, we were flying low over the city and slowly gaining height, when the plane suddenly turned round and flew ba