16周周测

孕育健康宝宝，从孕期检查开始（第12-16周生一个健康、聪明的宝宝是每一个家庭的共同愿望。

但是在我国仍有13.20‰的先天缺陷儿出生,因此所有有条件的孕妇都应该参加产前筛查,防止先天缺陷儿的出生。

通过孕期检查，了解孕期母婴健康状况，及时发现和消除影响胎儿发育的有害因素，及时发现和消除影响胎儿发育的有害因素。

检查项目:出生缺陷的初步筛查:如唐氏综合症等。

必要时建议羊水穿刺检查。

B超检查、白带支原体及衣原体检查、尿常规检查、骨盆检查、宫颈利片检查、肝肾功能检查、血液病毒学常规检查唐氏儿筛查准妈妈在怀孕14—17周时要傲唐氏儿筛查，这是一项染色体的检查。

如出现可疑或阳性，应做羊水或静脉穿剃己确诊监儿染色体是否正常。

35岁以上的准妈妈更有必要徽此项检查。

TIP:1.在做血液检查前一天，晚餐最好在自己家吃，在检查当天早上7点到9点的空腹时接受检查最适合。

2抽血当天不要穿袖口过小、过紧的衣服，避免抽血时衣袖无法上卷或抽血后衣袖过紧，引起手臂血管血肿。

B超检查作用:观察宝宝的样子，诊断胎儿的发育情况、羊水量及胎盘有无异常等。

正常妊娠检查一般做3次B超。

分别是16—20周之间:23周左右。

36周以后。

超声波检查对孕妇和胎儿一般没有伤害，只是把一个叫探头""的东西放在孕妇的肚子上，医生检查时就是拿着探头在肚子上来回移动，仔细观察屏幕上的画面。

TIP;孕中后期，医生会建议你做一个彩超，看看有没有脐带绕颈、脐脑动脉的血流好不好等。

怀孕12-16周胎儿的发育状况第12周孕早期在本周即将结束了，3个月来您和宝宝都发生了巨大的变化。

怀孕第12周的时候胎儿身长可达到6.5厘米，现在宝宝已经初具人形。

宝宝的成长速度在本周越发惊人。

12周的时候，宝宝整天忙着在妈妈的肚字里边做伸展运动，一会儿伸伸胳膊，一会儿踢题腿，您的肚子经常从表面上看上去凹凸不平就象一个水球。

在本周宝宝的手指和脚趾完全分开,部分骨胳开始变得坚硬。

七年级数学第16周测试题班级_______________ 姓名___________ 得分_____一、单选题：本大题共9小题，每题3.0分共27.0分；1、下列关于总体的说法正确的是（）A．总体是指我们所要考察的对象 B．我们要考察的对象叫做总体C．我们所要考察对象的全体叫做总体 D．总体是我们所要考察对象的个数2、为了了解黄冈市2004年中考6万余名考生的考试情况，从中抽取500名考生的成绩进行质量分析，在这个问题中，下列说法正确的是（）A．6万余名考生是总体 B．抽取的500名考生是总体的一个样本C．每名考生是个体 D．6万余名考生的成绩是总体3、一组数据的最大值与最小值之差为80．若取组距为9，则分成的组数应是( )A 7B 8C 9D 124、2000年某区有15000名学生参加高考，为了考查他们的数学考试情况，评卷人抽取了800名学生的数学成绩进行统计，那么下列四个判断正确的是( )A．每名学生的数学成绩是个体 B．15000名学生是总体C．800名考生是总体的一个样本 D．上述调查是普查5、为了了解一批冰箱的性能，从中抽取了10台进行检查试验，这个问题中10台冰箱的性能是( )A 总体B 个体C 样本D 样本数目6、下列说法正确的是( )A．只有通过普查才能够获取总体的特征 B．抽样调查是获取数据的唯一途径C．普查比抽样调查方便得多 D．抽样调查时的样本应具有随机性7、下列调查中，不适合做普查而适合作抽样调查的是( )A．审核书稿中的错别字 B．对中学生的身高情况进行调查C．对中学生目前的睡眠情况进行调查 D．对某地区的卫生死角进行调查8、下列调查的样本中缺乏代表性的有( )①为了了解你校七年级学生期中考试数学成绩，抽取七(一)班50名学生的成绩进行分析；②为了了解我国18岁青年的身高，从不同的地区随机抽取1000名18岁青年的身高；③为了了解一批洗衣粉的质量情况，从中抽取50袋进行检查；④为了了解某公园的每天游园人数，从中抽查一年中每个星期天的游园人数．A 1B 2C 3D 49、为了考察某班学生的身高情况，从中抽取20名学生进行测量，下列说法正确的是( )＿＿＿A．这个班级的学生是总体 B．抽取的20名学生是样本C．抽测的20名学生的身高情况就是全班学生的身高情况D．所抽测的20名学生的身高情况是总体的一个样本二、填空题：本大题共10小题，从第10小题到第17小题每题3.0分小计24.0分；第18小题为4.0分；第19小题为8.0分；共计36.0分。

16周b超看男女准确率孕妇在怀孕期间，会在一定的时期进行检查，去医院做b超，来看宝宝的发育情况，或者看宝宝是否是健康的，如果不健康就会立即采取措施。

当然在一定时期做b超的话还可能预测宝宝的性别是男还是女，这样一些家长就会根据孩子的性别给孩子取名字。

那么当怀孕16周时做b超看宝宝是男是女的准确率是多少呢？16周b超看男女准确率1、B超是通过观察胎儿的生殖器来判断是男孩还是女孩的，一般情况胎儿孕16周左右胎儿的生殖器就会形成，即在孕4月后可以通过B超来看胎儿性别，三维B超看胎儿性别的准确率会更高。

因为有的时候胎儿的生殖器可能会被胎儿的四肢挡住，所以最好多看几次以明确判断。

目前来说，通过B超看胎儿性别是比较科学的一种方法，准确率比较高。

但出于多方面的考虑，我国已明确禁止医生向孕妇或其家属透露胎儿性别。

2、民间流传从B超数据中的孕囊大小可以看性别，其实并没有任何科学依据。

孕囊的形状大小是由孕期时间、营养、着床位置、宫腔大小等多种因素决定的。

每个孕妈的宫腔不同，孕囊的形状自然随着宫腔形状而不同，而且还与孕妇检查时的状况有关，例如有的孕妇由于憋尿时间较长，子宫被压得扁一些，孕囊的形状也看起来扁一些。

另外，有的孕妇怀孕时精子和卵子的着床位置正当，有的位置会偏一些，导致孕囊形状也不同。

怀孕几个月b超可以准确知道胎儿性别即便是最有经验的影像学专家也得在妊娠三个半月或者三个月以上，准确率也不能达到100%，另有一项检查，就是利用孕妇末梢血，也就是毛细血管血，从孕妇耳垂上采血几滴，制成血涂片，经过特殊染色，利用细胞形态学的技术，来鉴定胎儿的性别，此项检查比较安全，要求条件，妊娠45天以上就可以。

以上就是小编整理的16周b超看男女准确率资料了。

现在大家已经知道怀孕16周做b超看胎儿性别的准确率啦，但是话说回来，不管宝宝是男孩儿还是女孩儿，都是爸爸妈妈的心头宝，爸爸妈妈都会爱他，所以也不要太在意孩子的性别情况了。

高三周周测试卷及答案 Final revision on November 26, 2020高三第16周周测语文试卷第I卷阅读题―、现代文阅读（35分）（一）论述类文本阅读（9分，每小题3分）阅读下面的文字，完成1～3题。

关于中国古文字的产生时代这一问题始终缺乏具体确切的答案。

就是世界各国的文字学专家，对于文字产生的具体时代也有着不同的见解和学派。

一种说法，认定文字的起源并不比语言产生晚，认为人类早在旧石器时代或新时器时代初期就产生了文字。

持这种观点的人，主要把人类最早的图画、图示和各种刻记纳入了文字的范围。

他们把原始人的许多岩画谓之“图画文字”；也有把纹文时期的纹记视作正式的文字。

这主要是对文字的真正定义和内涵缺乏一个正确的认定。

当然我们很容易想象人类没有形成语言的时候，他们要表达某种意念或某种信息，只好用手势比划或在地上画图表示。

但是文字终归是文字，它和那些原始的辅助表意手段有着根本的区别，这个根本的区别是不管世界上哪个民族的文字，没有一个不是他们民族语言的符号，尽管世界文字之林中有的是表意文字，有的是表词文字，有的是标声文字，但都是和他们自己民族的语言一致的，凡是语言能表达的，文字就能表达。

所以可以说文字尽管在某种功能上超出了语言，但仍然是语言的辅助工具。

这样的文字，自然是产生在语言产生以后。

还有一种观点也是不能使人认同的。

那就是拘泥于实证主义的研究方法，即没有见到完整的实证材料，就认定事物的不存在，就对没有被认识或没有被发现的甚至对理应存在和实际有过但已消失的事物持一完全否定的态度。

这种实证主义的方法并非是科学的态度。

比如说，在中国古文字起源的研究中，很多人认定殷商时期的甲骨文就是最古老的汉字，可在甲骨文被发现以前，人们长期认为商周时期的金文是中国最古老的文字。

这些一见实物就动辄定论的习惯，一直妨碍了对文字起源的系统地、理论地探讨，也难以形成一个科学的客观的明晰结论。

当然，甲骨文是比金文更为古老的汉文字，有一些甲骨文的单字比钟鼎文的结构带有更为原始的特征，如“”（子）、“”（午）、“”（丁）等。

第16周第八十八回禅到玉华施法会心猿木母授门人精题演练1.师徒四人到达（天竺）国下郡玉华县,县中城主,封为（玉华王）2.三个王子爱好武艺,大王子拿着一条（齐眉棍）,第二个抡着一把（九齿耙）。

第三个使一根（乌油黑棒子）正好与悟空兄弟的兵器相似:孙悟空使的是（金箍铁棒）,猪八戒使的是（九齿钉耙）,沙和尚使的是（降妖宝杖）3.为什么这个章回作者强调悟空三人兵器的具体重量?突出悟空三人的力量大，也解释三个王子为什么拿不动悟空的兵器。

4.你喜欢“玉华城收徒”这个故事吗?为什么?不喜欢因为显得悟空爱炫耀，喜欢因为股市生活化，为下文豹头山妖精偷兵器埋下伏笔。

第八十九回黄狮精虚设钉钯宴金木土计闹豹头山精题演练1.偷兵器的妖怪住在（豹头）山（虎口）洞,是一个（黄狮）精2.行者在山背看到两个狼头妖怪,一个叫（刁钻古怪）一个叫（古怪刁钻）3.妖精被打败后奔到（竹节洞）,那山中有一座洞,唤做（九曲盘桓洞）,洞里的老妖是（九灵元圣）4.行者、八戒、沙僧是如何进入妖洞的?八戒，行者分别变做买猪羊的小妖刁钻古怪、古怪刁钻,沙僧变做贩猪羊的客人,伪装走进虎口洞里。

第九十回师狮授受同归一盗道缠禅静九灵精题演练1九头脚子精是（太乙救苦天尊）的坐骑（九头狮）2九头脚子精跟黄精定的计谋是什么？黄狮等用心拿那行者、沙僧;九头狮子暗自飞空上城,擒拿唐僧和玉华王父子,先转九曲盘桓洞;黄狮精得胜后回洞集合。

3阅读选段,回答同题狮奴道:“爷爷,我前日在大千甘露殿中见一瓶酒,不知偷去吃了,不觉沉醉睡着,失于拴锁,是以走了。

”1这是讲哪个妖怪下界的原因?文中的“爷爷”指谁?九头狮子精(九灵圣元);太乙救苦天尊。

2你能从以前的阅读中找到和这个相类似的情节吗?太上老君守牛的童子在丹房拾得一粒丹吃了,睡了七天,使牛栏里的青牛无人看管,下界为妖。

第九十一回金平府元夜观灯玄英洞唐僧供状1师徒四人路过（金平）府慈云寺打斋,寺里僧人留过（元宵）节看灯,唐僧在（金灯）桥上看灯时,被妖怪摄去。

初一下学期第16周英语周测一、单项填空（20分）1.( ) —Did you hear of __________boy called Jim? Yes, he is ________ honest boy.A. a; theB. a; aC. a; anD. the; an2.( ) ___________ works Zhu Ziqing’s are!A. What good B How good C. What well D How well3.( ) Jim made a nice cage _____________ the little sick bird till it could fly.A. keepB. keptC. keepingD. to keep4.( ) Cross the bridge and then walk ____________ the market.A. towards toB. overC. towardsD. from to5.( ) ---We will have a picnic next month. ---Really? __________great fun!A. What aB. WhatC. HowD. How a6.( ) Eastern Star(东方之星) capsized(船翻) on June 1st in the water of Yangtze Riverand more than four________________ people lost their lives.A. hundredsB. hundreds ofC. hundredD. hundred of7.( ) —_________ I take my cousin Shirley with us, Mr Wu？—Yes, but we’ll get there by bike. ____________ she ride a bike?—Yes, and she ___________ ride a bike when she was only six years old.A. Could; can; couldB. Can; can; canC. Can; could; couldD. Could; could; can8.( ) The oranges in her garden are ____________________.A. enough sweet to eatB. sweet enough to eatC. enough sweet to eat them D sweet enough to eat them9.( ) ___________ is it from the hotel? It is about 40 minutes ___________.A. How far; take a busB. How long; by busC. How far; by busD. How long; take a bus10.( ) Stephen lives in a ___________ flat with a big balcony. And he often chats withhis friends _________ the balcony.A. four bedrooms; inB. four-bedroom; onC. four bedrooms; onD. four-bedroom; in11.( ) —Are you willing to live on Mars(火星)?—___________ It sounds exciting, but it still worries me.A. Of course I am.B. I’m not sure.C. Why not?D. Are you joking?12.( ) He likes to sleep with the windows ____________.A. openB. openedC. openingD. opens13.( ) —It’s cold here. —OK. I___________ the window.A. closedB. will closeC. closeD. was closing14.( ) My father is ill. He is still in ____hospital. I’m going to _____hospital to see him.A. the; theB. a; theC. /; theD. the; /15.( ) The man can write with ______ hand and draw with ______ at the same time.A. one; anotherB. one; the otherC. first; secondD. one; it16.( ) My uncle’s dog was in the garden. I saw him _______ under the tree.A. to lieB. lyingC. liedD. is lying17.( ) _______ beautiful park it is and _______ happy the children are in it!A. What, howB. What a, howC. What a. whatD. How a, how18.( ) Listening to the ______ story always makes me ______ .A. exciting ; excitingB. excited ; excitedC. exciting ; excitedD. excited ; exciting19.( ) There ____ a talk show on CCTV-4 at eight this evening .A. is going to beB. will haveC. is going to haveD. is having20.( ) —_______you help me with my homework? —Of course if I________.A. Could; couldB. Can’t; canC. Could; canD. Can; could二、完形填空（10分）On my way home I knocked into a man when he 1 ."Oh. I'm terribly sorry," I said.‘That's all right. Please excuse me too; I didn’t even 2you. I wish(希望) I didn't hurt you." We were very3. We said good-bye and went on our way.But at home we often treat (对待)our loved ones in a different way.Later that day, when I was cooking the evening meal, my daughter stood beside me very quietly. When I turned, I nearly 4 her down. " Move out of the way." I shouted. She walked away, tears(眼泪) in her eyes. When I lay in bed, I realized(意识到) how 5 I'd spoken. So I decided to get up to say sorry to my daughter. On the way to her bedroom, to my surprise, I found some 6 by the door of the kitchen. At that time my tears began to fall.I quietly went and got down on my knees by her 7 . She woke up and put her arms around my neck . Then I asked," Did you pick these flowers for me?" She smiled," I found them by the tree. I picked them 8 they're like you. I knew you'd like them. I stood quietly because I wanted to give you a 9 .'"'Oh dear, I'm really sorry for the way I acted today; I shouldn't have shouted at you." “That's okay. Mom. I love you anyway."I suddenly realized what a clever way it is to explain(解释) the word 10 like this: ( F) ather (A) nd ( M) other, ( I) ( L) ove ( Y) ou !( ) 1. A. passed by B. walked past C. past D. past by( ) 2. A. save B. help C. call D. notice( ) 3. A. sad B. angry C. polite D. happy( ) 4. A. put B. took C. knocked D. turned( ) 5. A. sadly B. rudely C. softly D. happily( ) 6. A. books B. clothes C. flowers D. vegetables( ) 7. A. bed B. desk C. chair D. door( ) 8. A. if B. because C. but D. so( ) 9. A. surprise B. party C. present D. picture( ) 10. A. father B. mother C. family D. daughter三阅读理解（30分）AIt was the Greek shopkeeper who taught me about the power of being kind.In 2008, I left Spain to study alone in London. My parents had to bring up(养育) my three younger sisters and two younger brothers, so I found three part-time jobs to pay for my studies. I worked early mornings and late nights, so I was tired, really tired, all the time.Unluckily, I got a cold and had a very high fever. Because I was new in London, I had no friends. Besides, I was too shy to talk with others and ask others for help. After sleeping on the bed for two days, I went out to get some food. Usually, I went to the supermarket, but this time I went into the Greek shop, a small corner shop, because it was closer.I picked up some food and gave it to the shopkeeper, who asked me, ‘You look terrible, my boy! You are not feeling well, right?’I said YES in a low voice.She pointed at the salami (腊肠) and bread I was buying and offered, ‘I can make you a sandwich, so you don’t have to do it yourself.’I nodded without saying a word.So, she made the sandwich and asked me to wait a moment. She went into the back room and came again with a bowl of hot soup.‘It will warm you up,’she said with a friendly smile. What really warmed me up was not the soup. It was her smile that told me she cared me. Her kindness(善良) made me think of my mother.I was quite shy, but from that day on, I did not let shyness stop me from talking with and being kind to others. Now I work in a children’s hospital in Africa. I love my work and people around me. I always bring my smile and kindness to them.( ) 1. When did the writer leave for London?A. In 2003.B. In 2009.C. In 2008.D. 10 years ago.( ) 2:What can we learn about the writer and his family?A. His parents could not pay for his studies.B. There are five kids in his family.C. The writer is the youngest child in the family.D. In 2008 the writer left London to study in Spain.( ) 3. What happened to the writer?A. He lost his part-time jobs.B. He had a talk with his friends.C. He got a cold and had a very high fever.D. He was not popular at his school. ( ) 4. What did the shopkeeper not do for the writer?A. She made the sandwich.B. She cooked a bowl of hot soup.C. She made some bread.D. She sold him some salami. ( ) 5. Which of the following words can’t describe(描述) the Greek shopkeeper?A. Friendly.B. Shy.C. Nice.D. Kind.B“Make-A-Wish”is one of the world’s most famous charities (慈善机构) . It makes wishes(愿望) come true for children who is badly ill. It gives them hope and joy and helps them forget about their health problems and have fun.It all started in 1980 in Phoenix, Arizona. Christopher was a 7-year-old boy who was very sick. He always dreamed of becoming a police officer. Tommy Austin and Ron Cox, two police officers , made his wish come true .They gave Christopher a tour of the city in a police helicopter(直升飞机) and made a real police uniform(制服) for him.There are four kinds of wishes children usually have:I wish to go. Children usually want to travel or go to a concert, a game or a park.I wish to meet. Children sometimes want to meet their favorite actors, singers or players.I wish to be. Some children wish to become actors, singers or police officers.I wish to have. They often want to have a computer, a game, a bike or many other things. Let’s hope more wishes will come true in the future. People who work in the charity always try for the best .Almost 25,000 volunteers(志愿者) help, work or give money. Will you be one of them?( ) 6. “Make-A-Wish”is a charity to help __________________.A. sick childrenB. serious officersC. famous actors(演员)D. popular singers ( ) 7. What did the two police officers do for Christopher?A. They give him a computer.B. They give him a tour of the city.C. They took him to a concert.D. They took him to the hospital.( ) 8. Which kind of wishes does Christopher have?A.I wish to goB.I wish to meetC.I wish to beD.I wish to have ( ) 9. The purpose of the last paragraph is to ______.A. explain(解释) what “Make-A-Wish” isB. encourage(鼓励) more people to join the charityC. tell us how Christopher’s wish came trueD. introduce(介绍) different kinds of children’s wishes( ) 10. Which of the following is TRUE according to the passage?A. Sick children just wish to get well.B. Christopher and Tommy are two officers.C.A few people are working for ‘‘Make-A-Wish’’.D. “Make-A-Wish” has a history of over 30 years.CLong ago the people of Taiwan were happy. They were farmers, but they also hunted animals and fished on their beautiful island. However, one day the Sun and the Moon disappeared(消失)! The people were scared(惊恐的) and didn’t know what to do.A young couple called Dajiange and Shuishejie went to look for the Sun and the Moon. They crossed rivers and mountains and walked through dark forests. They could not find the Sun or the Moon. One day they came to a mountain. It was beside a lake. They could see lights in the lake and two dragons playing with the Sun and the Moon. The dragons threw the Moon to each other. They kicked the Sun and used their tails to play with the Sun. The young couple wanted to help the Sun and the Moon.Then an old lady appeared. She told them that she was the dragons’cook, but she didn’t like them. She told the young couple how to kill the dragons. “You will need the golden scissors(剪刀) and the axe(斧头) from Ali Mountain.”The young couple looked all day and night in the mountain to find golden axe and scissors. At last, they found them and threw them into the lake. The dragons were killed and the Sun and the Moon were free. Now the young couple need to put the Sun and the Moon back in the sky. The cook told them to eat the dragon’s eyes. After they ate the eyes, they became giants(巨人). They used trees to hold the Sun and the Moon up in the sky. Everyone was happy again.Over thousands of years the giants became two mountains. They are now called Dajian Shan and Shuishe Shan. The lake is now called “the Sun and Moon Lake”.( )61. Why were the people scared?A. Because they hunted animals.B. Because there was no fish on the island.C. Because the Sun and the Moon disappeared.D. Because they like the Sun and the Moon. ( )62. In paragraph2,what were the dragons doing?A.Cooking the Sun.B.Swimming.C.Kicking the Moon.D.Throwing the Moon to each other.( )63. What happened to the giants?A. They became dragons.B. They became mountains.C. They got married.D. They moved to Taiwan.( )64. How did the giants put the Sun and the Moon back in the sky?A. The dragons helped them.B. They held them in their arms.C. They kicked them.D. They held them in the sky using trees.( )65. Which is the best title of the passage?A. The Sun and the Moon Lake.B. The Sun and the Moon.C. Two Giants.D. Two Dragons.四词汇（20分）1.It is his ____________(four) time to come to Beijing.2.If you must go, at least wait till it stops _______________(rain).3.From then on, ____________(kite) flying became a very popular activity.4.He ____________(wake) up and found himself alone in a long low hall.5.We ______(hide) his stick here yesterday, but we can’t find it now.6.I do everything ______(careful) to make it happy and healthy.7.When he came to the yard（院子）, he noticed that the door was _______(lock).8.I was surprised______(know) that it was only a dream.9.The_____(weigh) of the tortoise（乌龟）is 7kg.10.I didn’t hear the bell because it was too_____(noise) in the classroom.11.I think Simon has all the ______(able) to be a good leader of our class.12.If you don’t try, you will fail______(win) the match.13.My friend didn’t notice me _______(stand) at the corner at that time.14.We decide ________(get) a carry-out pizza for dinner.15.Mrs Wu_______(teach) us Maths last term.16.This is the ______(good) restaurant of all in Zhenjiang.17.I saw Lin Tao______(feed) his dog Sam when I came back.18.I found a book of ______(she) on the ground.19. A big fish swam under their boat and ______(bite) holes in it.20.Mr Green wants to teach my parrot_______(speak) English.五看音标写单词（10分）1.['pəʊɪm]___________2. [faɪt]___________3. [tʌtʃ]_________4. ['enɪweə] ____________5. [rɪ'piːt]_____________6. [ə'griː]_______________7. [weɪ] ______________8. [,vaɪə'lɪn]_______________ 9. ['ɑːtɪkl]______________ 10. _['həʊmtaʊn] ___________六连词成句（10分）1. it’s very small and soft and I can hold it in my hand___________________________________________________________________.2. there’s nothing wrong with keeping a snake if you like it_____________________________________________________________________.3. dogs like exercise a lot, so we walk him in the park every evening____________________________________________________________________.4. she never worries because we take good care of her_______________________________________________________________________?5. How big can goldfish grow?_______________________________________________________________________.。

§6.3 电容器 带电粒子在电场中的运动班级＿＿＿＿＿＿＿＿姓名＿＿＿＿＿＿＿＿学号＿＿＿＿＿＿＿＿成绩＿＿＿＿＿＿＿＿一、选择题1、某电解电容器上标有“25v ，470μF ”的字样，对此，下述说法中正确的是 ( )A.此电容器只能在直流25v 以下电压才能正常工作B.此电容器必须在直流25v 的电压时才能正常工作C.当工作电压是直流25v 时，电容才是470μFD.这种电容器使用时，必须考虑电容器的两根引线的极性2、如图所示，在开关S 闭合时，质量为m 的带电液滴处于静止状态，那么下列判断正确的是 ( )A ．开关S 断开，极板上电荷量将减小，电压降低B ．开关S 断开，极板间距离减小，则极板上电荷量减小C ．开关S 断开．极板间距离减小，则极板间的电压减小D ．开关S 断开，极板间距离减小，则带电液滴向下运动3、如图所示，接通S 使电容器充电．当增大两极板间距离时，电容器所带电荷量Q 、电容C 、两板间电势差U ，电容器两极板间场强E 的变化情况是 ( )A ．Q 变小，C 变小，U 不变，E 变小B ．Q 变小，C 变小，U 不变，E 不变 C ．Q 不变，C 变小，U 变大，E 不变D ．Q 不变，C 变小，U 变小，E 变小4、一平行板电容器始终与电池相连，现将一块均匀的电介质板插进电容器恰好充满两极板间的空间，与未插电介质时相比 ( )A ．电容器所带的电荷量增大B ．电容器的电容增大C ．两极板间各处电场强度减小D ．两极板间的电势差减小5、如图所示是一个由电池、电阻R 与平行板电容器组成的串联电路．在增大电容器两极板间距离的过程中 ( )A ．电阻R 中没有电流B ．电容器的电容变小C ．电阻R 中有从a 流向b 的电流D ．电阻R 中有从b 流向a 的电流6、如图所示，要使静电计的指针偏转角变小，可采用的办法是 ( )A ．使两极板靠近；B ．减小正对面积；C ．插入电介质；D ．用手碰一下负极板。

八年级（下）数学第十六周测 班级______姓名___________1、在下列命题中，结论正确的是（ ）．A ．平行四边形的邻角相等B ．平行四边形的对边平行且相等C ．平行四边形的对角互补D ．沿平行四边形的一条对角线对折，这条对角线两旁的图形能够完全重合 2、下列各分式中，最简分式是（ ）A 、()()y x y x +-8534B 、y x x y +-22C 、2222xy y x y x ++D 、()222y x y x +- 3、把多项式416x -分解因式，结果是（ ）A ．2(4)x -B ．22(4)(4)x x +-C ．2(4)(2)(2)x x x ++-D ．2(2)(2)x x +- 4、在ABCD 中，AC 、BD 相交于O ，AC=10，BD=8，则AD 的长度的取值范围是（ ）．A ．AD>1B ．1<AD<9C ．AD<9D ．AD>95、如果(3)26m x m +>+的解集为2x <，则m 的取值范围是（ ） A ．0m < B ．3m <- C ．3m >- D ．m 是任意实数6、若使代数式312m -得值在1-和2之间，则m 可以取的整数有（ ）A ．1个B ．2个C ．3个D ．4个7、若不等式组213x x a -<⎧⎨<⎩的解集是2x <，则a 的取值范围是（ ）A ．2a <B ．2a ≤C ．2a ≥D ．2a >8、一件工作，甲独做a 小时完成，乙独做b 小时完成，则甲、乙两人合作完成需要（ ）A ．11a b ⎛⎫+ ⎪⎝⎭小时B ．1ab小时 C ．1a b+小时 D ．aba b+小时 9、下列美丽的图案，既是轴对称图形又是中心对称图形的个数是（ ）（A ）1个 （B ）2个 （C ）3个 （D ）4个C10、在四边形ABCD 中，AD ∥BC ，当满足条件（ ）时，四边形ABCD 是平行四边形．A ．∠A+∠C=180°B ．∠B+∠D=180°C ．∠A+∠B=180°D ．∠B+∠C=180° 二、填空题：（每小题3分，共15分）11、若1212x x x x +-÷-+有意义，则x 的取值范围是 。

2021-2022年高三上学期周周清（16）生物试题含答案一、选择题(本题共小题，每小题分，共分)1.关于细胞的叙述，正确的是( )A.所有的细胞均含有溶酶体B.大肠杆菌的转录和翻译可同时进行C.胆固醇是构成植物细胞膜的重要成分D.原核细胞不含叶绿体，不能进行光合作用2.下列有关物质运输的叙述，正确的是( )A.小分子物质不可能通过胞吐的方式运输到细胞外B.细胞中蛋白质的运输必须经过内质网C.RNA聚合酶和DNA聚合酶都可经核孔运输D.葡萄糖只能从高浓度一侧向低浓度一侧运输3.下列关于细胞代谢的描述，正确的是( )A.破伤风杆菌有氧呼吸的产物是二氧化碳和水B.原核生物主要在拟核区转录形成信使RNAC.细胞凋亡和细胞坏死是基因选择性表达的结果D.细胞体积越大物质运输速率越高，代谢速率越快4.如图为细胞膜结构图，其中a和b分别代表不同分子或离子进出细胞的方式。

据图分析下列叙述正确的是( )A.不同膜结构③的排列方式不同B.神经细胞受到刺激产生兴奋是Na离子通过②进入细胞，此过程不消耗ATPC.b可表示组织细胞从组织液中吸收氧气D.将③分子制成微球体用来包裹大分子药物，送入到相应的细胞中，该过程体现了细胞膜的功能特点5.下列有关酶的叙述，正确的是( )A.所有酶水解的产物都是氨基酸B.酶为生化反应提供了活化能C.不同的细胞可能含有同一种酶D.酶只能在细胞内起催化作用6.下列有关酶和ATP的叙述不正确的是( )A.酶和ATP的化学成分中都含有氮元素B.分化程度不同的活细胞中酶和ATP的含量都不同C.细胞中基因的表达过程都需要酶和ATP的参与D.酶的合成和分解分别与ATP的合成和分解相联系7.下列有关绿叶中色素的提取和分离实验的叙述中，正确的是( )A.叶绿素的提取需要加入层析液作为提取液B.过滤时应使用单层尼龙布，并用棉塞塞住试管口C.分离色素时应将滤液细线置于层析液中D.选材不同，四条色素带在滤纸条上的排列顺序不同8.下列与癌变相关的叙述不正确的是( )A.癌症的发生并不是单一基因突变的结果B.免疫系统能监控并清除人体内的癌变细胞C.原癌基因或抑癌基因突变可导致癌症，因此癌症可遗传D.癌变前后，细胞形态和结构有明显差别9.科学家利用“同位素标记法”弄清了许多化学反应的详细过程。