S1: Certain protective devices are fitted in the motor circuit. S2: They can protect against faults such as single phasing, overload or under voltage. Q: Which one is not mentioned?
单选题
Please inform us at once in an emergency case. 遇到紧急情况，请立即通知我们。
单选题
The generators should run without sparks and noises 发电机运行时应无火花和噪音。
单选题
Keep the electrical equipment clean, it is essential for good operation. 保持电气设备的清洁，这是良好运行的必要条件。
