Directions: This section is to test your ability to comprehend short passages. You will hear a recorded passage. After that you will hear five questions. Both the passage and questions will be read two times. When you hear a question, you should complete the answer with a word or a short phrase (in no more than 3 words). You should write your answer to each question correspondingly. Now the passage will begin.[音频]1. Who are Henry and Jane?.2. Where did they rent an apartment?.3. How many rooms does their apartment have?4. Why do Henry and Jane often ride bicycles in the park?5. Where can Henry and Jane go any time?
用万用表测量开关好坏应调到()档位
A. 欧姆档
B. 蜂鸣档
C. 电压档
D. 电流档
人体同时接触带电设备或线路中的两相导体时,电流从一相通过人体流入另一相,这种触电现象称为( )触电。
A. 单相
B. 感应电
C. 两相
D. 以上都是
下列说法中,不正确的是()
A. 正弦交流电的周期与角频率的关系互为倒数
B. 交流电每交变一周所需的时间叫做周期
C. 规定小磁针的北极所指的方向是磁力线的方向
D. 交流发电机是应用电磁感应的原理发电的