题干

为了安全,汽车行驶时驾驶员必须系安全带.汽车上设置了“安全带指示灯”提醒驾驶员系好安全 带.当安全带系好时,相当于闭合开关,指示灯不亮;安全带未系好时,相当于断开开关,指示 灯发光.图中符合上述要求的电路图是( )

A:

B:     

C:

D:

上一题 下一题 0.0难度 选择题 更新时间:2019-10-19 08:08:33

答案(点此获取答案解析)

B

同类题2

阅读下列内容,从每小题所给的A、B、C、D四个选项中选出一个最佳答案。

    When I was young, I wanted a dog. But my parents always said I was too young. They suggested getting another kind of pet. But I wanted a dog, so I waited. When my parents thought I was old enough at last, I got Luke. From then on, I learned that having a dog was really hard work.

                                                                                                                                 -Kate

Cinder and I became good friends about a year ago. Cinder is my dog. I named her Cinder because my name is Cindy. I think the name Cinder sounds nice. I got the dog on my twelfth birthday. The next morning, I went to the library to find out some information about how to take care of the dog.

-Cindy

I'm in Grade Four at the Blake School. My pet hamster(仓鼠), Lightning, lives in our classroom. She is brow n and white. I got my hamster two years ago. My friend Jason and I gave each other a hamster for our birthdays. I brought my hamster to school once and the other kids liked her. I decided to leave her there, because my parents hated having Lightning in the house.

                                                                                                                               -David