题干

小明家的电路简化后的示意图如图所示,关于该电路,下列说法正确的是(   )

A:白炽灯、电视和台灯是串联在电路中的

B:开关和白炽灯串联后接在火线和零线之间

C:各个小彩灯之间是并联的

D:去掉空气开关不影响电路的工作和安全

上一题 下一题 0.0难度 选择题 更新时间:2016-09-02 11:28:12

答案(点此获取答案解析)

B

同类题1

阅读下面一首诗歌,完成小题。

莱蒙托夫

                                                                                             那大海上淡蓝色的云雾里

                                                                                             有一片孤帆儿在闪耀着白光!……

                                                                                             它寻求什么、在遥远的异地?

                                                                                             它抛下什么、在可爱的故乡?……


                                                                                             波涛在汹涌——海风在呼啸,

                                                                                             桅杆在弓起了腰轧轧地作响……

                                                                                             唉!它不是在寻求什么幸福,

                                                                                             也不是逃避幸福而奔向他方!


                                                                                            下面是比蓝天还清澄的碧波,

                                                                                            上面是金黄色的灿烂的阳光……

                                                                                             而它,不安的,在祈求风暴,

                                                                                             仿佛是在风暴中才有着安详!

同类题5

阅读理解

    Every day, a homeowner in Pennsylvania is reminded of a mistake he made 13 years ago. At around 8 in the evening, his peaceful house comes alive with the noise of an alarm clock he dropped into the wall over ten years ago. It's been stuck in the wall ever since.

    13 years ago, Jerry Lynn wanted to make a hole through his living room wall, so he could pass the television cable (电缆)through it. He didn't want to destroy any pipes in the wall, so he came up with a good idea to make sure that he was drilling(钻孔) in an empty place. He took his alarm clock, tied it to a string(线) and set it to go off in 10 minutes. Then he lowered it into the wall, and waited for it to ring. His goal was to drill a hole in a safe place near the place where the ringing was coming from, making sure that there was nothing to pass through there. It all went smoothly until the alarm clock fell into the wall.

The man didn't get back the alarm clock, but thought it would probably run out of battery(电池)in several months, so he wasn't too worried about it. But 13 years later, the alarm clock still rings every day.

    As you can imagine, Jerry and his wife have gotten used to the ringing living room wall, but it can still surprise  guests. So Jerry decides to pull down that wall, just to stop that boring thing, though after putting up with it for 13 years, he think it will be a pity. He says, “I've never herd of a clock battery lasting that long and my friends think it may be interesting to see how long it will keep ringing for.”