电力电子逆变器双闭环电路仿真模型/整流器适用-In this section, you will hear five short conversations. Each conversation will be read only once. At the end of each conversation, there will be a twenty-second pause. During the pause, read the question and the three choices marked A, B and C, and decide which is the best answer. Then mark the corresponding letter on the answer sheet with a single line through the centre.