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3.单项选择

1)     Only time will ________ if this agreement will bring a lasting peace.

A. speak  B. tell   C. say   D. talk

2)     The phone was ringing, but by the time she _________ indoors, it __________.

A. got; stopped   B. had got; stopped 

C. got; had stopped   D. had got; had stopped

3)     “I have to go,” she said, and with _______ she hung up the phone.

A. it  B. which  C. that   D. whom

4)     He bought the tickets ________ a friend at the stadium.

A. through   B. thorough   C. though   D. throughout

5)     Recycling saves energy, ________ acid rain, global warming and air pollution

A. so reduces   B. so reducing   C. thus reduces  D. thus reducing

6) --- ______ is it today?   --- It’s Tuesday.

  A. When   B. What time  C. What date   D. What day

7) Jack, together with his friends, _______ to climb out of the canyon.

A. decide   B. has decided   C. are to decide   D. are deciding

8) ______ exists music everywhere in our life! Shall we sing together?

  A. There   B. Where   C. Wherever   D. Therefore

9) The room, _________, is pleasant and airy. I love it very much.

  A. being small   B. it is small   C. but small   D. though small

10) Language are taught by the direct method, _________ , without using the students’ own language.

  A. believe it or not  B. to tell the truth  C. that’s to say   D. generally speaking

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2.词形变化

1)     Exercise is the ideal way to reduce _________ (tense) after a hard day.

2)     I’ll be ________ (thank) for a good night’s sleep after the busy week I’ve had.

3)     Many old people are living by ________ (them) and they fell lonely.

4)     He wrote a _________ (thrill), which told an exciting story about murder or crime.

5)     I’ve had such a _________ (tire) day. I just want to take a bath and go to bed.

6)     He works as a ___________ (translate) changes writing into a different language.

7)     It is ___________ (tradition) not to eat meant on Good Friday().

8)     We all had to go on a special ___________ (train) course to learn new sales techniques.

9)     As a seasoned (有经验的) ___________ (travel), I know the value of being able to speak at lease a few words of the local language.

10)   He was __________ (terrify) at the thought of being trapped in the woods.

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1.单词拼写

1)     Water boils at a t________________ of 100 degrees centigrade.

2)     The storm brought strong winds, t___________ and lightning.

3)     T________ is the dried brown leaves that are smoked in cigarettes.

4)     Every year we look for buried t___________ and we hope to find valuable things such as gold, silver and jewels.

5)     Gerry was born in China and his mother t_______________ is Chinese.

6)     She does some TV work, but t_________________ (戏剧)remains her first love.

7)     The teacher gave out copies of the new t_______________ (时间表) in the first class.

8)     Luke put out his hand and touched the t_____________ (微小的)fingers of the baby daughter.

9)     There’s a huge queue in the ladies’ t______________ (厕所).

10)   A lot of old t______________ (传统) are dying out.

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5.句子翻译

1)   在学习方面爸爸对我要求很严格。(strict)

2)   他们成功找到了治疗头痛的方法。(succeed)

3)   爸爸的背不好。(suffer)

4)   这场演出不适合儿童观看。(suitable)

5)   她在转行进入新闻业之前是一名图书管理员。(switch)

6)   Ben向警察提供了那些涉案人员的姓名。(supply)

7)   我们强烈支持你的计划。(support)

8)   这孩子在音乐方面有天赋。(talent)

9)   他把信撕成碎片,扔到垃圾箱里。(tear)

10) 他们谈话的声音很低,我听不到他们说什么。(talk)

高三英语核心词汇复习第24课时

(tell--- treat)

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4.选词填空

sweep   swear   success  straight   target   swing   swell  tease   task  strengthen

1)     The experiment was a big _________; the professor got what he wanted.

2)     The road was dead _______ and it had no bends at all.

3)     Our friendship has steadily ________ over the years.

4)     I didn’t mean to make you mad; I was only ____________.

5)     Ann had the ________ of preparing the agenda for meetings.

6)     I set myself a _________ of learning 20 new words a week. I hope I can achieves the goal.

7)     Let your arms ________ as you walk.

8)     Put some ice on your injured knee before it ________ up.

9)     Thunderstorms __________ the country and caused a huge loss.

10)   Dad _______ not to smoke again, but mum didn’t believe his promise.

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3.单项选择

1) --- What would you like?  --- Steak or chicken would _________.

  A. suit me fine   B. be fit   C. be suitable   D. be good

2) The ______ of this experiment were all men aged 18-35, and they were asked to write down how they felt during the test.

  A. students   B. subjects   C. surgeons   D. strangers

3) Suddenly an idea _______ me and I found it would be a perfect solution to our problem.

  A. submitted   B. struck   C. sucked   D. subscribed

4) They suggest ______ to a lawyer before I do anything.

  A. me talk   B. me to talk   C. my talking  D. I will talk

5) --- You said you’d have finished by today.  --- I said __________!

  A. not a such thing   B. such a not thing   C. such no thing  D. no such thing

6) The health expert ________ the importance of a balanced diet.

  A. stressed   B. strengthened   C. struggled   D. supported

7) The meeting _______ take place on Tuesday, but we’ve had to delay it.

  A. was subject to  B. was supposed to   C. was sure to   D. was suited to

8) Peter was suspected ______ government secrets to the enemy.

  A. to give off   B. of giving off   C. to give away  D. of giving away

9) As we all know, the dove is a ________ of peace.

  A. symbol   B. system   C. sign   D. symptom

10) Roger _____ painting for a while, but soon lost interest.

  A. took on   B. took in   C. took up   D. took over

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2. 介词填空

1)     All ______ a sudden, the lights went out.

2)     Your computer is far superior _______ mine.

3)     No one knows _______ sure what really happened.

4)     I have absolutely no sympathy _______ students who get caught cheating in exams.

5)     Were you successful ________ persuading him to change his mind?

6)     Millions of people are struggling __________ survival.

7)     Janet’s been __________ a lot of stress since her mother’s illness.

8)     Tom looked up ________ surprise as Dale walked in.

9)     The palace is surrounded _______ a high wall.

10)   Why don’t you come over ______ supper on Friday?

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1.单词拼写

1) --- Where’s the station?  --- Sorry, I’m a s________ here myself.

2) Before choosing a career you should know your personal s________ and weaknesses.

3) The TV sex educational program is aimed at t____________, not adults.

4) Modern t_________ makes it possible for people to live longer than before.

5) Dead leaves floated on the s___________ of the water.

6) My possessions were a s_____________(衣箱) full of clothes and books.

7) A brief s_____________ (概要) is given on a separate sheet.

8) Tom is a regular customer in the s________________ (超市).

9) If you drink some water, it will make the pills easier to s_______________(吞咽).

10) These sausages are really t______________ (可口的). Where did you buy them?

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数学教材是学习数学基础知识、形成基本技能的“蓝本”,能力是在知识传授和学习过程中得到培养和发展的。新课程试卷中平面向量的有些问题与课本的例习题相同或相似,虽然只是个别小题,但它对学习具有指导意义,教学中重视教材的使用应有不可估量的作用。因此,学习阶段要在掌握教材的基础上把各个局部知识按照一定的观点和方法组织成整体,形成知识体系。

学习本章主要树立数形转化和结合的观点,以数代形,以形观数,用代数的运算处理几何问题,特别是处理向量的相关位置关系,正确运用共线向量和平面向量的基本定理,计算向量的模、两点的距离等。由于向量是一新的工具,它往往会与三角函数、数列、不等式、解几等结合起来进行综合考查,是知识的交汇点。

(1)向量的加法与减法是互逆运算;

(2)相等向量与平行向量有区别,向量平行是向量相等的必要条件;

(3)向量平行与直线平行有区别,直线平行不包括共线(即重合),而向量平行则包括共线(重合)的情况;

(4)向量的坐标与表示该向量的有向线条的始点、终点的具体位置无关,只与其相对位置有关系;

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题型1:平面向量的概念

例1.(1)给出下列命题:

①若||=||,则=

②若ABCD是不共线的四点,则是四边形ABCD为平行四边形的充要条件;

③若==,则=

=的充要条件是||=||且//

⑤ 若////,则//

其中正确的序号是      

(2)设为单位向量,(1)若为平面内的某个向量,则=|;(2)若与a0平行,则=|;(3)若平行且||=1,则=。上述命题中,假命题个数是(   )

A.0               B.1               C.2               D.3

解析:(1)①不正确.两个向量的长度相等,但它们的方向不一定相同;

②正确;∵ ,∴

ABCD是不共线的四点,∴ 四边形 ABCD为平行四边形;反之,若四边形ABCD为平行四边形,则,

因此,

③正确;∵ =,∴ 的长度相等且方向相同;

,∴ 的长度相等且方向相同,

的长度相等且方向相同,故

   ④不正确;当//且方向相反时,即使||=||,也不能得到=,故||=||且//不是=的充要条件,而是必要不充分条件;

   ⑤不正确;考虑=这种特殊情况;

   综上所述,正确命题的序号是②③。

点评:本例主要复习向量的基本概念。向量的基本概念较多,因而容易遗忘。为此,复习时一方面要构建良好的知识结构,另一方面要善于与物理中、生活中的模型进行类比和联想。

(2)向量是既有大小又有方向的量,与||模相同,但方向不一定相同,故(1)是假命题;若平行,则方向有两种情况:一是同向二是反向,反向时=-||,故(2)、(3)也是假命题。综上所述,答案选D。

点评:向量的概念较多,且容易混淆,故在学习中要分清,理解各概念的实质,注意区分共线向量、平行向量、同向向量等概念。

题型2:平面向量的运算法则

例2.(1)如图所示,已知正六边形ABCDEFO是它的中心,若==,试用将向量表示出来。

(2)(06上海理,13)如图,在平行四边形ABCD中,下列结论中错误的是(    )

A.  B.+  C.  D.+

(3)(06广东,4)如图1所示,D是△ABC的边AB上的中点,则向量(   )

A.      B.

C.       D.

(1)解析:根据向量加法的平行四边形法则和减法的三角形法则,用向量来表示其他向量,只要考虑它们是哪些平行四边形或三角形的边即可。

因为六边形ABCDEF是正六边形,所以它的中心O及顶点ABC四点构成平行四边形ABCO

所以=+= =+

由于ABOF四点也构成平行四边形ABOF,所以=+=+=++=2+

同样在平行四边形 BCDO中,+(+)=+2

点评:其实在以ABCDEFO七点中,任两点为起点和终点,均可用 表示,且可用规定其中任两个向量为,另外任取两点为起点和终点,也可用表示。

(2)C.

(3),故选A。

例3.设ABCDO是平面上的任意五点,试化简:

,②,③

解析:①原式=

②原式=

③原式=

例4.设为未知向量,为已知向量,解方程2-(5+3-4)+ -3=0

解析:原方程可化为:(2 - 3) + (-5+) + (4-3) = 0,

=+

点评:平面向量的数乘运算类似于代数中实数与未知数的运算法则,求解时兼顾到向量的性质。

题型3:平面向量的坐标及运算

例5.已知中,A(2,-1),B(3,2),C(-3,1),BC边上的高为AD,求

解析:设D(x,y),则

所以

例6.已知点,试用向量方法求直线(为坐标原点)交点的坐标。

解析:设,则

因为的交点,所以在直线上,也在直线上。

即得,由点得,

得方程组,解之得

故直线的交点的坐标为

题型4:平面向量的性质

例7.平面内给定三个向量,回答下列问题:

(1)求满足的实数m,n;

(2)若,求实数k;

(3)若满足,且,求

解析:(1)由题意得,所以,得

(2)

(3)

由题意得,得

例8.已知

(1)求

(2)当为何实数时,平行, 平行时它们是同向还是反向?

解析:(1)因为

所以

(2)

因为平行,所以即得

此时,则,即此时向量方向相反。

点评:上面两个例子重点解析了平面向量的性质在坐标运算中的体现,重点掌握平面向量的共线的判定以及平面向量模的计算方法。

题型5:共线向量定理及平面向量基本定理

例9.(2002天津文12,理10)平面直角坐标系中,O为坐标原点,已知两点A(3,1),B(-1,3),若点C满足,其中αβ∈R,且α+β=1,则点C的轨迹方程为(   )

A.3x+2y-11=0                   B.(x-1)2+(y-2)2=5

C.2xy=0                       D.x+2y-5=0

解法一:设,则

于是,先消去,由

再消去,所以选取D。

解法二:由平面向量共线定理,

时,A、B、C共线。

因此,点C的轨迹为直线AB,由两点式直线方程得即选D。

点评:熟练运用向量的加法、减法、实数与向量的积的坐标运算法则进行运算;两个向量平行的坐标表示;运用向量的坐标表示,使向量的运算完全代数化,将数与形有机的结合。

例10.(1)(06福建理,11)已知︱︱=1,︱︱=,=0,点C在∠AOB内,且∠AOC=30°,设=m+n(mn∈R),则等于(  )

A.        B.3       C.     D.

(2)(06湖南文,10)如图:OMAB,点P由射线OM、线段OBAB的延长线围成的阴影区域内(不含边界).且,则实数对(x,y)可以是(  )

A.   B.

C.      D.

解析:(1)B;(2)C。

题型6:平面向量综合问题

例11.已知向量的对应关系用表示。

(1)证明:对于任意向量及常数m,n恒有成立;

(2)设,求向量的坐标;

(3)求使,(p,q为常数)的向量的坐标

解析:(1)设,则

(2)由已知得=(1,1),=(0,-1)

(3)设=(x,y),则

∴y=p,x=2p-q,即=(2P-q,p)。

例12.求证:起点相同的三个非零向量,3-2的终点在同一条直线上。

证明:设起点为O==3-2

=2(),=

共线且有公共点A,因此,ABC三点共线,

即向量,3-2的终点在同一直线上.

点评:(1)利用向量平行证明三点共线,需分两步完成:① 证明向量平行;② 说明两个向量有公共点;

⑵用向量平行证明两线段平行也需分两步完成:①证明向量平行;②说明两向量无公共点。

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