3.单项选择
2. 句子改写
1) Dave borrowed the CD player from me. = I _______________________ Dave. (lend)
2) Jerry didn’t tell me the truth. = Jerry ___________________ me. (lie)
3) Lucy will probably come tomorrow. = Lucy _______________ tomorrow. (likely)
4) 50 sailors were killed at sea. = 50 sailors ______________ at sea. (lose)
5) There are small shops on both sides of the street.
= The street ______________ small shops. (line)
6) Most of the students like pop music. = ____________ enjoy pop music (majority)
7) They write prices on the goods. = Goods ___________________ prices (mark)
8) Nobody cares about what you wear. = ___________________ what you wear. (matter)
9) There are 10 doctors in the rescue team. = The rescue team ___________________. (make)
10) If you miss the bus, you’ll have to wait another 15 minutes.
= Missing the bus _____________________ minutes. (mean)
1.单词听写
1) You can go to the l____________ to borrow the books you want.
2) One has to go through some tests to get a driving l____________.
3) Water is known to exist in three different states as a solid, l___________ or gas.
4) Hand l______________ is the small bags you carry with you when traveling on a plane.
5) There was a great summer storm, with thunder, l_____________ and heavy rain.
6) She’s the editor of a popular women’s m____________.
7) The research shows that one in three m_________ ends in divorce.
8) As many as 3,000 children died of hunger and lack of m____________ care.
9) It’s hoped that there will be direct flights between Taiwan and the m___________.
10) The writer is collecting m_____________ (材料)or his new novel.
5.句子翻译
1) 他们执意要唱卡拉OK。(insist)
2) 这个讲座持续了3个小时。(last)
3) 吃太多糖会导致健康问题。(lead)
4) Alex真正的问题是缺乏信心。(lack)
5) 这个岛有一座桥与大陆相连。(join)
6) 依我看,他们都应承担责任。(judge)
7) 这些旧房子就要被拆掉了。(knock)
8) Nitrous oxide通常被称为笑气.(know)
9) 别让他在外边的雨中等着.(leave)
10) 100多名乘客在这起坠机事故中丧生.(kill)
高三英语核心词汇复习第14课时
(lemonade– mess)
4.选词填空
junior leak learn interview innocent land last keep interrupt introduce
1) Despite the bad weather, their flight ________ safely.
2) Cut flowers will ________ longer if you put flower food in the water.
3) The kangaroo was _________ to the country form Australia.
4) Eat the vegetable as soon as possible --- it does not _______ well for long.
5) While I was giving my report, Tom kept _________ me every two minutes.
6) Water was ___________ from a pipe in the bathroom.
7) She was surprised to __________ that he was a lot older than she had thought.
8) She started to work as a __________ reporter on a local newspaper.
9) We’ve _______ a woman for the job already, but she isn’t very well qualified.
10) The court found him ______________ and he was set free.
3.单项选择
1). --- I really need to speak to you now. --- Oh, all right if you __________.
A. invite B. insist C. lead D. know
2) If Jo can’t attend the meeting, I could go _______________.
A. instead B. though C. latter D. just
3) --- Who knows how to use the new machine? --- Why not follow the _________.
A. intention B. institution C. introductions D. instructions
4) The book is ____________ for children aged 5-7, it has many interesting stories.
A. instructed B. intended C. learned D. kept
5) We’re sitting over there. Why don’t you ____________ us?
A. join B. join in C. take part D. take part in
6) I’d say she’s pretty rich, ________ by her expensive clothes.
A. to judge B. being judged C. judging D. to be judged
7) I’ve been really busy _______, so I haven’t been out much.
A. late B. latter C. later D. lately
8) He __________ a bunch of flowers at the place where his friend was killed.
A. lied B. lay C. laid D. lain
9) _________ coffee is in the form of powder and prepared by adding hot water.
A. Instant b. Immediate C. Quick D. Fast
10) We would have arrived much earlier if ________ hadn’t been for the snow.
2.词形变化
1) He refused to answer any questions until his _______________ (law) came.
2) Thanks for your _____________ (invite). I’d love to come.
3) The computer will start by _______________ (it) in a few seconds.
4) It is ___________ (legal) to sell tobacco to someone under 16.
5) The teacher tried to make his students _____________ (interest) in biology.
6) The dishwasher is a wonderful ______________ (invent).
7) All the boys enjoyed listening to the ____________ (inspire) success story.
8) He looked shocked, and then burst into ______________ (laugh).
9) I can’t thank you enough for your _______________ (kind).
10) The United ____________ (king) is made up of England, Wales, Scotland, and Northern Ireland.
1.单词拼写
1) The teacher encourages his students to watch bees and other i__________.
2) Not all English learners want to become i______________ or translators.
3) IN the i___________ the author explains why he wrote the book.
4) She worked as a j_______ on The New York Times.
5) Jay’s in the k___________ washing the dishes.
6) Johnson is a scientist at the Massachusetts I_____________ (学院) of Technology.
7) The country is made up of hundreds of i__________.
8) Some of my aunt’s j__________ has gone.
9) He regularly gives i____________ on modern French literature.
10) He doesn’t have the skills or k________ needed for the job.
常用的抽样方法及它们之间的联系和区别:
类别 |
共同点 |
各自特点 |
相互联系 |
适用范围 |
简单随机抽样 |
抽样过程中每个个体被抽取的概率是相同的 |
从总体中逐个抽取 |
|
总体中的个数比较少 |
系统抽样 |
将总体均匀分成几个部分,按照事先确定的规则在各部分抽取 |
在起始部分抽样时采用简单随机抽样 |
总体中的个数比较多 |
|
分层抽样 |
将总体分成几层,分层进行抽取 |
各层抽样时采用简单抽样或者相同抽样 |
总体由差异明显的几部分组成 |
不放回抽样和放回抽样:在抽样中,如果每次抽出个体后不再将它放回总体,称这样的抽样为不放回抽样;如果每次抽出个体后再将它放回总体,称这样的抽样为放回抽样。
随机抽样、系统抽样、分层抽样都是不放回抽样。
题型1:统计概念及简单随机抽样
例1.为调查参加运动会的1000名运动员的年龄情况,从中抽查了100名运动员的年龄,就这个问题来说,下列说法正确的是( )
A.1000名运动员是总体 B.每个运动员是个体
C.抽取的100名运动员是样本 D.样本容量是100
解析:这个问题我们研究的是运动员的年龄情况,因此应选D。
答案:D
点评:该题属于易错题,一定要区分开总体与总体容量、样本与样本容量等概念。
例2.今用简单随机抽样从含有6个个体的总体中抽取一个容量为2的样本。问:① 总体中的某一个体在第一次抽取时被抽到的概率是多少?② 个体
不是在第1次未被抽到,而是在第2次被抽到的概率是多少?③ 在整个抽样过程中,个体
被抽到的概率是多少?
解析:(1),(2)
,(3)
。
点评:由问题(1)的解答,出示简单随机抽样的定义,问题( 2 )是本讲难点。基于此,简单随机抽样体现了抽样的客观性与公平性。
题型2:系统抽样
例3.为了了解参加某种知识竞赛的1003名学生的成绩,请用系统抽样抽取一个容量为50的样本。
解析:(1)随机地将这1003个个体编号为1,2,3,…,1003.
(2)利用简单随机抽样,先从总体中剔除3个个体(可利用随机数表),剩下的个体数1000能被样本容量50整除,然后再按系统抽样的方法进行.
点评:总体中的每个个体被剔除的概率相等,也就是每个个体不被剔除的概率相等
.采用系统抽样时每个个体被抽取的概率都是
,所以在整个抽样过程中每个个体被抽取的概率仍然相等,都是
。
例4.(2004年福建,15)一个总体中有100个个体,随机编号为0,1,2,…,99,依编号顺序平均分成10个小组,组号依次为1,2,3,…,10.现用系统抽样方法抽取一个容量为10的样本,规定如果在第1组随机抽取的号码为m,那么在第k小组中抽取的号码个位数字与m+k的个位数字相同.若m=6,则在第7组中抽取的号码是___________.
剖析:此问题总体中个体的个数较多,因此采用系统抽样.按题目中要求的规则抽取即可.
∵m=6,k=7,m+k=13,∴在第7小组中抽取的号码是63.
答案:63
点评:当总体中个体个数较多而差异又不大时可采用系统抽样。采用系统抽样在每小组内抽取时应按规则进行。
题型3:分层抽样
例5.(2006湖北文,19)某单位最近组织了一次健身活动,活动分为登山组和游泳组,且每个职工至多参加了其中一组。在参加活动的职工中,青年人占42.5%,中年人占47.5%,老年人占10%。登山组的职工占参加活动总人数的,且该组中,青年人占50%,中年人占40%,老年人占10%。为了了解各组不同的年龄层次的职工对本次活动的满意程度,现用分层抽样的方法从参加活动的全体职工中抽取一个容量为200的样本。试确定
(Ⅰ)游泳组中,青年人、中年人、老年人分别所占的比例;
(Ⅱ)游泳组中,青年人、中年人、老年人分别应抽取的人数。
解析:(Ⅰ)设登山组人数为,游泳组中,青年人、中年人、老年人各占比例分别为a、b、c,则有
,解得b=50%,c=10%.
故a=100%-50%-10%=40%,即游泳组中,青年人、中年人、老年人各占比例分别为40%、
50%、10%。
(Ⅱ)游泳组中,抽取的青年人数为(人);
抽取的中年人数为50%=75(人);
抽取的老年人数为10%=15(人)。
点评:本小题主要考查分层抽样的概念和运算,以及运用统计知识解决实际问题的能力。
例6.(2006四川文,5)甲校有3600名学生,乙校有5400名学生,丙校有1800名学生,为统计三校学生某方面的情况,计划采用分层抽样法,抽取一个样本容量为90人的样本,应在这三校分别抽取学生( )
A.30人,30人,30人 B.30人,45人,15人
C.20人,30人,10人 D.30人,50人,10人
解析:B;
点评:根据样本容量和总体容量确定抽样比,最终得到每层中学生人数。
题型4:综合问题
例7.(1)(2004年湖南,5)某公司在甲、乙、丙、丁四个地区分别有150个、120个、180个、150个销售点.公司为了调查产品销售的情况,需从这600个销售点中抽取一个容量为100的样本,记这项调查为①;在丙地区中有20个特大型销售点,要从中抽取7个调查其销售收入和售后服务情况,记这项调查为②.则完成①、②这两项调查宜采用的抽样方法依次是
A.分层抽样法,系统抽样法 B.分层抽样法,简单随机抽样法
C.系统抽样法,分层抽样法 D.简单随机抽样法,分层抽样法
分析:此题为抽样方法的选取问题.当总体中个体较多时宜采用系统抽样;当总体中的个体差异较大时,宜采用分层抽样;当总体中个体较少时,宜采用随机抽样.
依据题意,第①项调查应采用分层抽样法、第②项调查应采用简单随机抽样法.故选B.
答案:B
(2)(2005湖北卷理第11题,文第12题)某初级中学有学生270人,其中一年级108人,二、三年级各81人,现要利用抽样方法抽取10人参加某项调查,考虑选用简单随机抽样、分层抽样和系统抽样三种方案,使用简单随机抽样和分层抽样时,将学生按一、二、三年级依次统一编号为1,2,…,270;使用系统抽样时,将学生统一随机编号1,2,…,270,并将整个编号依次分为10段.如果抽得号码有下列四种情况:
①7,34,61,88,115,142,169,196,223,250;
②5,9,100,107,111,121,180,195,200,265;
③11,38,65,92,119,146,173,200,227,254;
④30,57,84,111,138,165,192,219,246,270;
关于上述样本的下列结论中,正确的是 ( )
A.②、③都不能为系统抽样 B.②、④都不能为分层抽样
C.①、④都可能为系统抽样 D.①、③都可能为分层抽样
解析:D。
点评:采用什么样的抽样方法要依据研究的总体中的个体情况来定。
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