题目

Because of his good work, John was ________ to a higher class. A. appointed        B. promoted                 C. proceeded                 D. selected 答案：B 解析: 略直线l过抛物线y2=4x的焦点F，交抛物线于A、B两点，且点A在x轴上方，若直线l的倾斜角，则|FA|的取值范围是    ．