1972-11-07 — Page 18

第二第十五第 日二月十年于壬腰夏

1973英文中學會考試題預習專欄:

英文科

(

Composition continous

Writing a composition 12

examinatzen condition alasys seemy ́easier to a student tras a the

classroom. About 400 ward to an nour's work is average.

must remember to keep to the polo and the way to succeed is to follow your plane

Your next step now 18---hon to start. Your market dust be made aware of what you are writing about as soon as possible.

A

stimulating beginning will arouse the interest of your readers. So, be sure that the opening sentence 18 correct and attractive.

There are many methods for starting. Take a look at this topic The Cross Harbour Turnel. First of all ask yourself:"What do I know about it?" Belevant

questions on What, Where, How and Why should be answered by yoursel: and appear in your plan. Newto start-----here are but a few suggestions.

1. The Cross Harbour Tunnel was officially opened on the twenty first of October, 1972 at 13:30pm. by H.R.H. Princess Alexandra. IE was the fruiffùl result of years of planning and constructing. Only time can really tell how useful ir really is. (Using a factual state- ment to introduce the topic straightaway: this is a direct approach method.)

The C.B. T. is the greatest piece of engineering venture H, K.

as ever undertaken and, to my relief, successfully accomplished. (Using your own opinion as an introduction to the topic. This

Ls another direct approach method

The next 4 methods belong to the indirect approach. Cautif oust be paid here. Do not forget fast this is only an introduction to your topic. Make it brief but to the point.

BSN It was 7.15 9.M. Not much.

brattic was on the road. As usual the only ones at the bus stops are students. I crossed the road easily and walked briskly to the Last stop. To my surprise, zis Dust one had a new sign on the post ----No. 101--- 50 this is the new cross harbour tunnel route, (Starting with a short description of scene or action that is associ- ated with the topics)

a na roour, as we all know, 1s a stretch of water between two pieces of land. At one time, it was not possible to drive directly from Kowloon peninsula to Hong Kong island because they are separated by the Victoria harbour: but now, with the opening of the CHUT. t is possible. (Using a short explanation of the topic to introduce it.)

One day, as I was standing In the outer office of a govern- ment department, I saw a sheepish-

looking boy speak stealthily beling the counter. At first I thought he was trespassing and was rboul to inform the guard. The next moment, a clerk behind the counter intercepted him and an arewent pursued. It turned out that he was the office boy and for

the them time that week, he was His excuse was---I missed LL

the lo. 102 bus.

As we all know, the muses SƏB Whose numbers are more than 100 re the C.H.T. buses... (Using a kort story that is associated o related to the topic.)

"Why do you choose to go To H.K. by bus? It 18 80 much quicker if you take the ferry

In my case, this is not 50.1 can take the 103. It is Custer and cheaper."

Using a conversation which teads to the topic)

B. When using the 5th and 6th. method, you must remember not to ike them fill your whole essay After you have looked over

YAT FO

報日僑華

Exercise

1973英文中學會考試題預習專欄

數學科

MATHEMATICS (3)

Problem solvable by anglysis into right angled triangle.

From geometry, we have the Pythagoras theorem

for a right-angled triangle. Hence if any two of the three $108 are given, the third side may be determined. Again, the two acute are complementary, so that if one 19 given, the other can also be found. Therefore in the solution of right-angled triangle, there are actually only 2 cases to be considered:

(1) When any two sides are given. (11) When any one side and one

acute angle are given.

Let us look at the following e.g.

Sxample A

A boat sailing against the wind from a place Y to a place Z due east of Y takes a course either N64°E or 564°E alternate- ly. What is the distance of 2 from Y if the boat has to travel 5000

ft?

Solution: Let A, B, C, be the turning points.

Let M, N, be the points where the boat meets the line YZ.

Then A AYH, BMN. CNZ are 2809.

From A,B,C, we drop perpendiculars AP, BQ, CR respect- ively to YZ.

Let YP-a It.

MQ = b ft. NRcft.

Then MAYP

Now YA

Adding.

YA

bc

BMQ =

=900-640

10 dec 26o ft.

MB

b sec 26° Ft.

c sec 26 ft.

have

MB NC

But YA Length of Theref

(a b+c)sec26 NC half the nourney #2500 ft

c)sec 259 → 2500

c=2500cos26° ft

2,500 cos26o ft. 4494 ft

ft

amene of radius 5 in

Sconical Tunnel whose ax19:

is ver

ical the NERUPS sphere is 207 vertex of the cone the_coce i

Solution

rests in

point. above Find

Let M be the vertex of the core Let R be the centre of the sphere Produce MR to meet the sphere again at S, which is the highest point of the sphere.

Let N be the point where the sphere touches the cone

MNR

90o

NR

sin RMN =

RMN 340 Therefore, The angle of the cone-2

=2134051 69 42

The six methods of starting an Assay, try them out with any topic Job, like, You will find that you

have more than one preference. Therefore Fructise these with different types of topics and before long you will realize that each method guts a different kind of title. snall leave you to decide your

method and approuch

二期星 日七月一十年二七九一届公年一十六國民華中青教僑華

新橋

A, B are two billiard balls at distances 20, 30" from a perfectly elastic wall CD The ball A is struck along and RB hits. B full on the

rebound after travelling al- together 70". Neglecting the

size of the balls and assuming

that AF, PB make equal angles. with CD, find the value of angle APB.;

(2) 2 towers A and B, on a level

plane subtend an angle of

90° at an abserver's eye, he walks directly towards

B & distance of 630 yds, and

then finds the angle subtend

-ed to be 143° 24". Find

the distance of A from each position of the observer:

Radian megsure

Definition: A radian is an angle

subtended at the centre of any

circle by an arc equal in length to the radius of the circle.. In our figure, o 18 the centre of the circle of radius units. If are PQ - r units,

/POQ - F

Suppose / POQ Then 3608

Where →

radian.

:1800

denotes

then

This is the formula confiécring circular measure in radione) asof the sedagesimal measure (in oekrës s) of an angle.

Remark

Since & radián is. consta rea, number, it is taken as a standard unit and the puster of radians contained 1.an any mang bers spoken of as 11s circular tẹnsurh In this system, an ariple is usualy ly denoted by a real number the unit being implied:

Length or an arc 01 8. Circle radica subtending an angle ✪ radian Sı its centre

With reference to the adyacent figure,

Length of arc PQ

circumference

211 radians 19

length of arc PQ

Area of a sector subtending the centre of a circle, radjustr.

With reference to the adjacent figure.

Area of sector POQ Area of the cimie

Area of sector POC

Example A

008

cos TcOT:

可有

REL | 簡 爲响晒此項運動之推行,對全港學生會,他們,不要做「垃圾車。 前,在家庭和學校赛,必須實立良好的橫柳,不一集可向公眾劃立一良好的抑檢。 想這個鎮做推行成功,澳生的腓力協助,是十分,请谍谱巷的各項活動。據指出:校是的全力留導一把作焦包括放健垃圾箱內」,一 本人更進一步呼籟,各位同邀在是税和的人,所有學校校舍及附近地方感俪常保持褥潮,因比」,「保捽郑村酒熙」、「保持前清潔」, 人特》全港清潔蓮動盤經于上河開始。 要亂丟棄物,看見別人亂丟廢物的時候,就勸告一損害健康」,「垃圾滋生病菌」 媒稱:目前安港藉過四分一的人是酷坐,聲特「清潔香港」,並確實質勵屬下資生顷和加放於垃圾箱內」,「把廢車票放垃圾 我臣可箸就此項運動復產啻各校校長鼎克」 「把選物被評垃圾窺內』 一,對促使全校員生參加清湖香港運動非常重要。一圾箱內」,「保持城市案」,「保持裾清潔 瑕」,「只有垃圾蟲避丢垃圾」

警

校潔教 覺內運

學

生

張動 貼獲

保全籲 持

清

潔行

之

標復以 語促

請作

以各則 提校

高校務

學長使

生在清

超濾一的分符宜内:

教育司署向學校大力鼓吹

全港清潔運動

LINTENTARES

台北學會發出呼籲 一反務倍上述一嚴打 | KETTAKERS.

DBER AWX ›

適此,有

當连束。

導語

張貼于佈告板上。

Examo

A wheel of radius r meter

rotating on its axis at w radi berond. Find the speed

point on the m

Solution: Let O be the centre of

the wheel A is an arbitrary point on the

TM

When OA turns through an angle of 2π radian, A moves a distance of: where r OA.

sec. UA tums through w radia

sec A moves a distance

Speed of A

Exerise

méter)sec.

(1). The arc of a circular sector 19 6 in, long, and the angle of the sector is

radian.

What is the area of the sector? In the figure, PQ and RS are arcs of concentric cirlea cur off by portions of two radii PS and QR 11 PS = RQ = 1 in,, are PQ - 5 in., are RS - ) 10. find the radi1 of the circles and the area of PQ RS.

Evaluate

Solution san

( 3 x 180) ∞ ( 14 ) d

7x4)

(94

(1) Express the following

angles in terms

600 1-350

(c) 45°

Express the following angles in degrees:

(a)