三相四线三元件有功电能表在测量平衡负载的三相四线电能时，若有两相电压断线，则电能表将 发布时间：2019-09-09 04:54 │ 来源：www.tikuol.com 题型：单项选择题 问题： 三相四线三元件有功电能表在测量平衡负载的三相四线电能时，若有两相电压断线，则电能表将（）。A.停转；B.少计2/3；C.倒走1/3；D.正常。
题型：单项选择题 用所给词的适当形式填空，其中有两项多余。feed, fresh, rubber, small, on, control, meat There are a lot of trees around us. The trees can help to make the air 1 and cleaner. They can also help to 2 the weather. They provide(提供) humans with food, 3 , medicine and other things. Because of the trees, many animals can live 4 the earth. But people often cut trees down in large numbers. The forests are becoming much 5 than before, so we should protect them well. 查看答案