题目

任务型阅读：（如果答案选E, 在答题卡上涂AB;选F，涂CD） Read the following text and choose the most suitable heading from A-F for each paragraph. There is one extra heading which you do not need. A．Reasons for the use of  Podcasting B．Definition and origin of Podcast C．Importance of Podcasting at school D．Advantage of Podcasts over other audio media E．Podcasts—a further step from voice recordings F．Devices needed for Podcasting定义运算则函数的最小正周期是 A 2        B         C        D