题干

如图所示电路,闭合开关后,两灯都不亮.为了检测电路故障,小华将电压表接在L2两端,发现电压表有明显示数,而电流表的示数几乎为零.则电路故障可能是(  )


A:灯L1短路

B:灯L2断路

C:电流表烧坏

D:灯L1断路

上一题 下一题 0.0难度 选择题 更新时间:2020-03-13 12:38:39

答案(点此获取答案解析)

B

同类题3

阅读下面短文,掌握其大意,然后从第1—20 各题所给的四个选项(A、B、C 和D)中,选出最佳选项。

    On a cold winter evening, I was walking home, tired and hungry, when suddenly came screams(呼喊声) from behind some tress.1, I slowed down to listen, and 2 that what I was hearing were the sounds of a fight. A woman was being3not far from where I stood.

    “Should I go to help her?” I thought. I was worried about my own 4,and I regretted having suddenly decided to take a new way home that night.“What if I am5too? Shouldn't I just6to the nearest phone and call the police?” But already the girl's7were growing weaker. I knew it was time for me to act fast because I could not8the life of this unknown woman,9 it meant risking my own life.

    I am not a 10 man. I didn't know where I found the11and physical strength(体力), but once I had finally12to help the girl, I became suddenly changed. I ran behind the bushes and 13the attacker off the woman. Struggling, we fell to the ground, where we fought for a few minutes 14the man jumped up and ran away.

    15 heavily,I stood up and came up to the girl, who was crying behind a tree. In the 16,I could not see her clearly, but I could certainly17her shock. Not wanting to frighten her any further, at first I spoke to her from a distance.

    “It's OK,” I said 18.“The man ran away. You're safe now.”There was a long stop and then I heard the words, said in both wonder and 19“Dad, is that you?” And then, from behind the tree, stepped my youngest 20, Katherine.

同类题4

                                                                                                想起那年读书时    谷煜
    ①那年我十岁,三年级,天不怕地不怕的年龄,不管生疏,常常和同学去串门。到了别人家里,我常常安静地直盯着土屋墙壁上的黑白报纸。那些报纸,是一些富裕人家不知从哪里弄来的,贴在墙上,给土屋一点美观,不至于到处露着暗灰的墙皮。 
    ②有字可读真好。看着看着,我的身子会趴下,因为靠底下的一些字实在是看不清了。而下面的报纸,往往更旧一些,泛着黄色,伴随着一丝丝潮潮的味道。而于我,是温润,是隆重,闪着华丽的光,仿佛是琥珀。 
    ③慢慢读完一面墙,真畅快呀。当时除了课本之外,再也找不到书可读,偶然在同学家发现这样的“报纸墙”,自是欣喜若狂,也就有了这“串门”的雅好。 
    ④慢慢地,很多人知道我喜欢“读字”,便有人告诉我,谁谁那里有小人书,可以借着看看。听了那些陌生的名字,怵头,我哪里认识人家呀?怎么办?只好央求妈妈去借,大人总会和人家说上话的吧。 
    ⑤那时候的小人书,人人当宝贝,自是不会轻易借出。妈妈便苦口婆心地求人家,一遍遍保证,不会弄丢的,不会弄脏的,不会弄扯的,一定按时还……终于,在人家一遍遍的叮嘱里,在犹豫的眼光里,我拿到了小人书。 
    ⑥我抱着书,飞奔回家,小心翼翼放在床头一角,赶紧吃饭写作业,然后扎在灯下,一声不吭,一页页仔仔细细看过去。夜深了,我抚摸着小人书,恋恋不舍地睡去,天亮,它就该物归原主了。 
    ⑦还有让人欢喜的是过年放鞭炮,因为那时很多鞭炮是用废弃的书本卷成的。鞭炮在炸开的刹那,产生很多带着字的碎片,它们仿佛一个个精灵,舞蹈着,纷纷朝我而来。我笑着跑着去迎接那些碎片,在碎片里,看到一个个的“断句”,或者几个词语,那种此起彼伏的文字阅读,仿佛海边的波浪,一波波的涌动而来,真好。 
    ⑧当然,也会有大的收获。包鞭炮的纸张总是大一些,我总是悄悄去捡来,展开,抚平,偶尔会读到一段故事,也许没有开头,也许没有结尾,但有一些词:万水千山,碧波荡漾,寂静芬芳,花来衫里,影落池中……它们总像是春天拂过的风,暖暖的,通身清透。 
    ⑨后来,我拥有了淋漓畅快的读书机会,全因为村里一户人家,做起了废品收购的买卖。他家的院子里,堆满了瓶瓶罐罐,纸箱书本。没有任何人邀请,我就成了人家的“座上客”,只要一有空闲,就跑到人家的院子里,那个小小的院落,被我的双脚一寸寸地丈量过。也是在那个时候,我看到了一本本完整的杂志,一本本很旧很破,几乎还是繁体字的《西游记》《后唐演义》……一路读起来,磕磕绊绊的,但总算能读过去。我坐在小小的院子里,一个有书的天地,令人满心欢喜。 
    ⑩慢慢地,条件好了,我去到乡里读书,可读的书多了起来。但是,却因为爱熬夜,受到了妈妈的限制。为了防止妈妈批评我,我钻在被窝里打着手电筒看,电池没得太快,也不是长久之策,就和妈妈打起游击战。 
    ⑪那时候没有雾霾,夜晚总是清亮亮的,我就盼着每个月的十五六,能在月光下看,但看得眼睛疼啊,试了几次之后,也就放弃了。⑵月光下,窗台边,一股清凉,几声蟋蟀鸣,是在我年少的记忆里最美好的场景。 
    ⑫后来啊,读书的种类,读书的场地慢慢丰富起来。不变的是,读书的每一个刹那,都仿佛是时光滋养的花枝,慢慢开出耀眼的花。多年以后,到底还是因为这书,生出了一些灵性,鲜亮了人生。蓦然回首,一路走来的读书时光,在阳光丽日里,散发着温暖、生动、可爱、亲切。一纸一片,在呼啦啦的青春里,依然于素色中呈现着夺目的光芒。素手拈花,好似故人来。这好玩的读书往事,想想就笑意盎然,关乎经脉,关乎底气,怎不值得终生记忆?