A. 邮票 B. 内件清单 C. 文件 D. 通信
A. when the engine RPM is pulled down by overload B. at rated engine RPM C. at 95 % of rated engine RPM D. at 95 % of a properly adjusted governor RPM with the engine under full load
A. 拨打120急救电话 B. 现场设法催吐、导泻 C. 保留食物样本 D. 就近送往医院治疗
A. 1~10Hz B. 10~20Hz C. 40~60Hz D. 100Hz~lkHz