题干

如图所示,若开关S闭合后,灯L1、L2均不亮,小华同学利用一根导线去查找电路故障,当她将导线连接在灯L1两端时,两灯均不亮,将导线连接在灯L2两端时,灯L1亮而灯L2不亮,由此可以判断(   )

A:灯L1断路

B:灯L2断路

C:灯L1短路

D:灯L2短路

上一题 下一题 0.0难度 选择题 更新时间:2018-06-28 11:31:13

答案(点此获取答案解析)

B

同类题5

完形填空

    I never thought I'd be a “runner”. I was the girl who 1 slowest in the PE class. A few years ago, I was walking with a group of2 in the Race for the Cure, a 5KM race designed to 3 money for the fight against breast cancer4 one lady caught my 5.

    She was one of the weakest-looking women I've ever seen. She must have been close to seventy years old,6a T-shirt with the word “Survivor.” She was so small that it seemed as if she could even be  7by a swift wind. But she was running. And she was 8 me my group of friends. She ran slowly, but 9—as if each step pushed her cancer further into her past. Right at that moment, I 10that in the next Race for the Cure, I'd be running along with her.

    A week later, I found myself in the11, running on the treadmill (跑步机). Three minutes after I started, my face was bright red. I felt like my lungs were going to12. I had to slow down to a walk. I thought of the 13at the race. I kept it up. I was able to go a little  14 each time. Three and a half minutes. Four minutes. Five.

    A year later, I was 15 at the Race for the Cure, but this time, I 16 with the runners. When the race started, the other runners passed me by. I ran forward. I wondered if I'd be 17 to do it. But then, I remembered the brave woman. I ran as fast as I could until I finally crossed that finish line. I had just 18 my first race! I looked down at my legs, 19. They had done something I'd never thought 20. I have never felt stronger than at that moment. And, I knew that I wanted to do it again.