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 ___________________________________

　　 是关于中国足球未来十年的发展。

　　 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(进入某种状态或发生某种情况)

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．在图中，是光滑的裸导线围成的线框，∠，线框处在水平面内且置于竖直向下、磁感应强度为的匀强磁场中，裸导线与线框良好接触，接触点、与线框顶点构成等边三角形，裸导线能在弹簧的作用下沿线框匀速向左移动，运动到顶点以后继续在光滑绝缘导轨上向左运动(绝缘导轨与光滑的裸导线围成的线框在同一水平面内，且光滑连接)；已知弹簧的平衡位置在点，导线的初始位置处在弹簧的弹性限度内，弹簧的劲度系数为，线框及导线单位长度的电阻为，裸导线的质量为.

(1)求向左做匀速运动的速度。

(2)从裸导线第一次运动到顶点开始计算，直到裸导线静止，电路中所产生的焦耳热是多少?

陕西省师大附中2009届高三第八次模拟考试

24、如图所示，摆锤的质量为，摆杆长为，其质量不计，摆杆初始位置与水平面成角，释放后摆锤绕轴无摩擦地做圆周运动，至最低点与质量为的钢块发生碰撞，碰撞时间极短，碰后摆锤又上升至点，、位于同一条直线上，钢块与水平面间的动摩擦因数为，求碰后钢块能滑行的距离。

23、如图所示，一起重机竖直吊起两个质量均为的重物和,以的速度向上匀速运动.当物体运动到距地面的高度为时,连接间的绳子突然断裂，绳子断裂后，起重机的拉力保持不变,不计空气阻力,取,求：

(1)从绳子断裂到重物落地所用的时间为多少？

(2)重物落地时,重物的速度大小为多少？

22、()在用单摆测定重力加速度的实验中，

①为了减小测量误差，如下措施中正确的是　　　 。(填字母)

A．单摆的摆角应尽量大些

B．摆线应尽量短些

C．选体积较小、质量较大的摆球　　

D．测量周期时，应取摆球通过最低点做为计时的起点、终点位置

E．测量周期时，应测摆球30-50次全振动的时间算出周期

F．将拴着摆球的摆线平放在桌面上，将摆线拉直后用米尺测出摆球球心到摆线某点O间的长度作为摆长，然后将摆线从O点吊起

②某学生在实验中，测出了多组摆长和周期的值，然后作出图象如图所示，并已测量计算出图线的斜率为。则由斜率求重力加速度的公式是=　　 。

()某同学为了测电流表的内阻精确值，有如下器材：

电流表(量程300，内阻约为5)；

电流表(量程600，内阻约为1) ；

电压表(量程15，内阻约为3) ；

定值电阻 (5) ；

滑动变阻器(0-10，额定电流为1)；

滑动变阻器(0-250，额定电流为0.3) ；

电源(电动势3，内阻较小)．

导线、开关若干．

(1)要求电流表的示数从零开始变化，多测几组数据，且电表的偏转必须同时达到以上，以保证有尽可能高的精确度．在如图所示线框内画出测量用的电路图，并在图中标出所用仪器的代号．

(2)若选测量数据中的一组来计算电流表的内阻，则所用电流表的内阻 =　　　 ；式中各符号的意义是　　　　　　 。

21. 如图所示，两个有界匀强磁场，磁感应强度大小均为，方向分别垂直纸面向里和向外，磁场宽度均为，距磁场区域的左侧处，有一边长为的正方形导体线框，总电阻为，且线框平面与磁场方向垂直，现用外力使线框以速度匀速穿过磁场区域，以初始位置为计时起点，规定：电流沿逆时针方向时的电动势为正，磁感线垂直纸面向里时磁通量的方向为正,外力向右为正。则以下关于线框中的磁通量、感应电动势、外力和电功率随时间变化的图象正确的是　　　　 (　　 )