【判断题】三相对称负载消耗的有功功率表达式为 P = 3 U p I p cos P = U L I L cos P ,式中 U p 、 U L 分别是相电压、线电压 (V) ; I p 、 I L 分别为相电流、线电流 (A) ; P 是相电压与相电流之间的相位差; P 是有功功率 (W) 。( )
【简答题】Listening Comprehension. 1. How does John go to school? A. By bike. B. By bus. C. By taxi. 2. What's Charlie's problem? A. He doesn't like English. B. He finds English homework difficult. C. He can't ...