【单选题】
词汇与结构 The flight instructor’s certificate must be renewed every 24 months by satisfactorily completing a flight instructor’s refresher course or a practical test designed to ________ aeronautical knowledge, pilot proficiency, and teaching techniques.
手机使用
分享
复制链接
新浪微博
分享QQ
微信扫一扫
微信内点击右上角“…”即可分享
反馈
收藏
举报
参考答案:
参考解析: