【Abstract】Non-English major students rarely study translation theory systematically， which requires teachers to penetra......

【Abstract】Writing is one of the most important skills that learners of English have to master， but it is difficult for ......

本文介绍一种用简易低频数字信号发生器做信号源,用晶体管PN结做温度传感器,用电压值显示相关测量位置声波振幅大小,频率、温度均......