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5. These new sports are called “extreme sports” and all centre on the “X-factor”.

Then my mind becomes clear and I concentrate on the way my body moves in the air.

centre on/concentrate on/ focus on(upon): keep all one’s effort or attention to sth

eg. He concentrated all his energies on studying.

　　 The subject of the conference ___________________________________

　　 是關(guān)于中國足球未來十年的發(fā)展。

　　 centres on the development of Chinese football in the future ten years.

4. The editors will decide if your idea is suitable and then send you rules and the form you need to apply for the record.　

apply for　 pay for　 ask for　 call for　 leave for　 wait for　 stand for　 look for　　 send for　　 make for　　 head for　　 long for　　 care for　 account for　 search for

1) She entered it, ____________a cup of coffee, and sat down.

2) He ________home ________the station just a few minutes ago.

3) Diana ________________you to have a talk with you outside the office.

4) The letters UN _____________the United Nations.

5) They have been______________ the missing child for two days.

6) He __________to the banker________ a loan last month.

7) After the death of their mother, the children ____________by an aunt until they grew up.

8) I saw the car _____________me , so I stepped aside.

9) I ____________you at 6 o’clock tomorrow morning.

10) Cultural exchange ________________better understanding.

11) You will have to ___________your selfishness some day.

12) We are all ____________the peace of the world.

13) He couldn’t ___________his absence for school these days.

asked for　 left; for　 is waiting for　 stand for　 looking for/searching for

applied; for　 had been cared for　 heading for　 will call for　 makes for

pay for　 longing for　　 account for

3. When IOC President Samaranch announced that Beijing would host the 2008 Olympic Games, all Chinese watching him on TV burst into cheers.

1) burst into tears/ cheers/ laughter…突然(進(jìn)入某種狀態(tài)或發(fā)生某種情況)

As soon as she saw me she burst into tears.

After these warm days we shall see the trees burst into leaf.

The orchards seemed burst into blossom over night.

2) burst out laughing/crying　　 He burst out crying like a child.

2. Instead, the editors of the book set down the records and keep track of them in other ways.　

　　 set down: write down; put or lay down　 I have set down everything that I can remember.

EX.　 Fill in the blanks with the proper phrases below.　

set about　 　set an example to　　 set aside　　 set back　 set down　 　　set fire

set foot　 　set out(off)　 　set free　 　set up　 set a record

1) He _____________all his important thoughts in his diary when they are fresh in his mind.

2) As soon as she arrived she ______________tidying up the room.　

3) Parents should __________________their children in behavior.

4) The old couple tried to _____________some extra money for some purpose.

5) The demonstrators ____________to the U.S. embassy in Britain.

6) The school _____________a special class to help those poor learners.

7) Having said goodbye to the friends, they____________ for their destination.

8) The old man ___________in his motherland again after 50 years.

9) You need to ____________the clock by 24 hours when you reach New York.

10) The slaves _____________at last after the Civil War.　

will set down　　 set about　 set an example to　 set aside　 set fire　

has set up　　 set off /out　　 set foot　 set back　　 were set free

1. More than 60,000 new records are sent in to the book each year, but they cannot all be printed.

send in: to send(a letter, piece of work for a competition,etc) to some central place

　　　 If you want a visa, be sure to send in your application in good time.

EX.　 Fill in the blanks with the proper phrases below.　

send for　 send back　 send off　　 send out　　 send up　　 send in

1) The sun _________________light and heat.

2) The Discovery __________________successfully on July 27, 2005.

3) The police _______________ when an emergency happens.

4) The whole family went to the airport _____________him________.

5) You must _______________your old driving licence with your application for a new one.

6) The T-shirt faded seriously. _________it ________to the shop.

sends out　 was sent up　　 are sent for　 to send; off　　 send in　　 Send; back　

25．在圖中，是光滑的裸導(dǎo)線圍成的線框，∠，線框處在水平面內(nèi)且置于豎直向下、磁感應(yīng)強(qiáng)度為的勻強(qiáng)磁場中，裸導(dǎo)線與線框良好接觸，接觸點(diǎn)、與線框頂點(diǎn)構(gòu)成等邊三角形，裸導(dǎo)線能在彈簧的作用下沿線框勻速向左移動，運(yùn)動到頂點(diǎn)以后繼續(xù)在光滑絕緣導(dǎo)軌上向左運(yùn)動(絕緣導(dǎo)軌與光滑的裸導(dǎo)線圍成的線框在同一水平面內(nèi)，且光滑連接)；已知彈簧的平衡位置在點(diǎn)，導(dǎo)線的初始位置處在彈簧的彈性限度內(nèi)，彈簧的勁度系數(shù)為，線框及導(dǎo)線單位長度的電阻為，裸導(dǎo)線的質(zhì)量為.

(1)求向左做勻速運(yùn)動的速度。

(2)從裸導(dǎo)線第一次運(yùn)動到頂點(diǎn)開始計算，直到裸導(dǎo)線靜止，電路中所產(chǎn)生的焦耳熱是多少?

陜西省師大附中2009屆高三第八次模擬考試

24、如圖所示，擺錘的質(zhì)量為，擺桿長為，其質(zhì)量不計，擺桿初始位置與水平面成角，釋放后擺錘繞軸無摩擦地做圓周運(yùn)動，至最低點(diǎn)與質(zhì)量為的鋼塊發(fā)生碰撞，碰撞時間極短，碰后擺錘又上升至點(diǎn)，、位于同一條直線上，鋼塊與水平面間的動摩擦因數(shù)為，求碰后鋼塊能滑行的距離。

23、如圖所示，一起重機(jī)豎直吊起兩個質(zhì)量均為的重物和,以的速度向上勻速運(yùn)動.當(dāng)物體運(yùn)動到距地面的高度為時,連接間的繩子突然斷裂，繩子斷裂后，起重機(jī)的拉力保持不變,不計空氣阻力,取,求：

(1)從繩子斷裂到重物落地所用的時間為多少？

(2)重物落地時,重物的速度大小為多少？

22、()在用單擺測定重力加速度的實(shí)驗中，

①為了減小測量誤差，如下措施中正確的是　　　 。(填字母)

A．單擺的擺角應(yīng)盡量大些

B．?dāng)[線應(yīng)盡量短些

C．選體積較小、質(zhì)量較大的擺球　　

D．測量周期時，應(yīng)取擺球通過最低點(diǎn)做為計時的起點(diǎn)、終點(diǎn)位置

E．測量周期時，應(yīng)測擺球30-50次全振動的時間算出周期

F．將拴著擺球的擺線平放在桌面上，將擺線拉直后用米尺測出擺球球心到擺線某點(diǎn)O間的長度作為擺長，然后將擺線從O點(diǎn)吊起

②某學(xué)生在實(shí)驗中，測出了多組擺長和周期的值，然后作出圖象如圖所示，并已測量計算出圖線的斜率為。則由斜率求重力加速度的公式是=　　 。

()某同學(xué)為了測電流表的內(nèi)阻精確值，有如下器材：

電流表(量程300，內(nèi)阻約為5)；

電流表(量程600，內(nèi)阻約為1) ；

電壓表(量程15，內(nèi)阻約為3) ；

定值電阻 (5) ；

滑動變阻器(0-10，額定電流為1)；

滑動變阻器(0-250，額定電流為0.3) ；

電源(電動勢3，內(nèi)阻較小)．

導(dǎo)線、開關(guān)若干．

(1)要求電流表的示數(shù)從零開始變化，多測幾組數(shù)據(jù)，且電表的偏轉(zhuǎn)必須同時達(dá)到以上，以保證有盡可能高的精確度．在如圖所示線框內(nèi)畫出測量用的電路圖，并在圖中標(biāo)出所用儀器的代號．

(2)若選測量數(shù)據(jù)中的一組來計算電流表的內(nèi)阻，則所用電流表的內(nèi)阻 =　　　 ；式中各符號的意義是　　　　　　 。

21. 如圖所示，兩個有界勻強(qiáng)磁場，磁感應(yīng)強(qiáng)度大小均為，方向分別垂直紙面向里和向外，磁場寬度均為，距磁場區(qū)域的左側(cè)處，有一邊長為的正方形導(dǎo)體線框，總電阻為，且線框平面與磁場方向垂直，現(xiàn)用外力使線框以速度勻速穿過磁場區(qū)域，以初始位置為計時起點(diǎn)，規(guī)定：電流沿逆時針方向時的電動勢為正，磁感線垂直紙面向里時磁通量的方向為正,外力向右為正。則以下關(guān)于線框中的磁通量、感應(yīng)電動勢、外力和電功率隨時間變化的圖象正確的是　　　　 (　　 )