第16题: [单项选择] The fires were thought to have been started A. purposefully. B. accidentally. C. on the Mexican border. D. in southern California. 参考答案:A 答案解析:从新闻中"Authority said they were seeking two men in connection with the fires,which they believed were
第17题: [单项选择]运行中的变压器,其交变磁通Φ() A. 仅穿过二次侧绕组 B. 先后穿过一、二次侧绕组 C. 仅穿过一次侧绕组 D. 同时穿过一、二次侧绕组 参考答案:D