1989-10-22 — Page 16

十七國民華中

育教 日三廿月九年巴己暦夏

鐵質對人體健康甚重要

兒童缺乏則影響腦發育

全球約有二成半嬰兒患缺鐵性貧血

然後特療程紧到說干為千,能質不良會產生在一 除在一張人出生就開始做存於對遇,

一,逅此,嬰幼兒時可能養不足對让战的影村, ... 波先重的鐵質不足攝入可修影响性治功能

九门北粤 数冲筏木

BK

木徑師着迷淹不息的不調,沿難爾戶德處,四季色彩為奇,加上

-

RENT DIRE

多團邈水战是合,對戶 「容合街;蕴師上奇處

火朝拍到将一斧請

T

1植造人

家化美

操為須 毋

天北室內轶旺办家翠蔣軒在拇行

新鴻基中心一艘商場的新陳列室坐巴 謝列室內備有最新系列的高質人 ament ER

翠詩杄市癆經理李惠儀发求:活於從艾怪手中奪回被布佰陧人很球單打冠

NFI L AL型周四射~相輝映,可算是最佳 一,碧加穿上以他命名的運動系列,倍添信心,邊與用品,

法國FILA運動裝

最新秋冬系列已抵港

些人造樹木和盆戏均以其術幹和質

ELLAERSKORAMOND

O AGENCIES LTD. MO

Art 118592大道办焘,他捧盃時也穿著 FILA- 運動裝系列,顯得格外神樂

西德網球巨星碧加贏取今居溫布頓大襄單打冠軍

·智與特楚體育用品部門店售逌新FILA轪冬運

·運動鞋,並於今年十月可以在各大百货公

200公司現般璃推廣 FLL A悵新各法

1990 中學會考盟專欄

ALL & DALE PRESS

Geography (3)

MOUNTAIN BUILDING PROCESSES

P. F. Chan

Plate tectonics provides the basic explanation for the formation of

mountains: DA the earth's surface. Three mountain building processes can

be identified as a result of the movement of plates.

M

A. Folding

4. Folding is the result:

compressional

forces acting

of

On

Fayers of rocks which are bent or -folded.

2. Types of felds

(a) Simple fold Asymetrical fold)

Both limbs are symmetrical.

j.e. of equal steepness

Anticline

unfold

(11) Syreline

- downfold

b) Asymmetrical fold

The axial plane is no longer

vertical and one limo is steeper

than the other!

(c) Overfold.

One limb has pushed over the other limb.

(d) Recumbent fold

One limb rests on the adjacent one and the two limbs are almost *parallel..

(e) averthrust

fold (nappe) the

rocks fracture, and one limb is thrust forward anto the other 1imb.

3. fold mountains..

Mountains which are made.. of folded rocks.

(a) The formation of fold mountain Sediments were deposited in vast depression or geosynclines As déposition continued, sediments were increased in weights and hardness, was turned- into sedimentary rock. The weight of the deposited material lead to

the slow sinking of the geosyncling. After millions of years, the sinking of the geosyncline. More together and these compressional forces caused the sedimentary layers to fold into high mountains..

(b) Types of fold mountains

(1) Old fold mountains

They were formed at a

they

earlier period it earth's history, but they are lower and less rugged because. weathering and erosion, 50 that эпту residual mountain masses remain.

Here are Stable zones, with rare

earthquakes and eruptions in volcanic recent times. Foxer. Old fold mountaing, -Hercynian fold mountains

(275 million years ago)

the Appalachians

e.g.

(V.S.A.)

1990 中學會考磐專欄

出版社

MILL & DALE PRESS

Demand And Supply I

A. Demand (continued).

Contents

Factors Affecting Demand

Elasticity

-Caledonian fold mountains

(400-million-years ago).

8.9. the

to

日二十一(九八九一)年八十七國民華中(16)

fragments.

into small

These fragments fall back

報日僑

日期星

the

thrust upward.

Scandinavia

compression

outer locks are

not,

The

Weathered

The solidified Java may be Form deep,

only

and

forces the outerblock to

override the area between

tha

fault" but

mountains

depresses the black

Highlands (Norway.

Sweden)

(41) Young

fold

B. Faulting

Alpine fold mountains) They were formed abount 35 million. years ago, therefore they are very high and very rugged. Instability, vulcanicity and frequent earthquakes occured in these zones. e.g. the Andes (South

America)

the Himalayas (India). the Rockies (North America):

1. A fault is a break in rock due to either. tensional or compressional movettents of the plates, long, which there has been

movement a. displacement of rock..

2. Types of faylt

(a) Normal fault

C. Vulcanicity

also central which become a valley. e.g. R. Rhine, the East African Rift Valley,

vulcanicity is the process by which magma is furced into the crust" ejected neto the surface.

1. Intrusive vulcanicity

(a) The magma stays and cod's within

the crust...

e. does not reach the surface,

intrusive

(b) Features formed

vulcanicity.

Baths th

DY

It is a huge ligneous: intrusion which decenes 10 great leptis.

is

11.

cr

cooled,

underground

very

and

slowly

often

mountain..

It is caused by tensional forces- and that one block slides down" relative to the other.

(b) Reverse fault

It is caused by compressional. forces and that one block is pushed up relative to the other. (c) Tear fault

It is produced by lateral ovement and that two blocks along a fault move horizontally in opposite directions.

3. (a) Block faulting

Earth movements may cause the crust to be divided into blocks. by a series of fault lines, i.e. several faults: fairly parallel to one another,

(4)

Block-mountain (horst).

A norst is formed by tensional Force. The central block is left upstanding by either one of the following:

(a) The sinking of the the Couterblock

outerside of aspir of normal fault

The uplift of the Central block between the So normal fault.

The harst. are usually. bordered by very steep slope caused fault: scarp.,

Bicck Forest in e.g.. Germany. (1) Tilt plock

The uplifted black tilted.

(iii) Rift Valley (Graben)

A rift valley is a long deep depression, it may be formed by either one of the following:

(a) It may be caused by tension and the sinking. of central block between two normal fault.

(b) It may be caused by compressional, two reverse fault have developed and

Economie & Public Affair (3)

Contents

Basic Assumptions.

T. Kwok

forms the reat

-Sometimes in

becomes

.exposed at the surface

through

prolonged weathering and uosion of the mountain.

(1) taccoliti

It is a large. intrusions of igneous rocks which form dome-shaped masses.

and

Magna streded solidified along a bedding plane of sedimentary rockS into a nor-vertical

An igneoUS crack

and metamorphic rocks.

(iv) Dyke

the of

Magma is cut across bedding planes sedimentary rocks or onto vertical cracks in ignenus and metamorphic rocks..

2. Extrusive culcanicity

TaMagma that reaches the fact dans called lave, it reaches the

ur face either than opening at the surface called a verit or through. 3. Tomack in the surface racks whi called a fissure.

(b) Types of lava

(1) Basic lava

It contains less silica..

It is a fluid lava and can Flow

distance' longer before it solidifies.

મૈં

(ii) Acid lava

It contains more silica.

It is viscous lava end can flow a shorter distance before it solidifies..

(c) Features formed by extrusive

Velcanicity.

4) Lava platform

of

Successive cutpouring Tava from Fissure builds up a platform-liked feature which buries the original landscape.

It is often composed of basic Java.

Supply

fertile back soil.. e.g. Deccan Plateun (India)

(11) Volcano

If lava reaches the surface via a vent ther it Sulds

up a cone-shaped round. (1). Lawn Cone

cone,

It is made up of lava only. The lava flows out quietly to build

the Up because

no explosive activity's involved. shapo and the slope of its sides depend upon the type of lava that forms it. a) Acid lova

The

{dore

volcanh) Viscous acid lava produces еспе with steep slopes. because the lava does not flow easily.

b) Basic tava cone (shield.

volcano

Fluid basic lava will build un gently stoping cone with

penn,

the

Bread

Lecause 'ava. flows easily. (2) Ash and cinder core What lava Solently ejected, it is blown up to areat heights and breaks.

to earth around, the vent

and builds up a cone

They

are steep-sided, concave slope.cone built up of ash. The finer ashes deposited

Tower on the slope.

(3) Composite cone The cone is made up of alternate layers of ash and lava Fach new eruption with great violence. produces ash and clinders. which fall back around the vent and form the basis of .the cone. With the vent cleared, lava now pours out more freely and it spreads out over the cone burying the ash and cinder, "ayer, Repeated violent ejections followed by flows of Tava build up a cone steadily in height.

Sometimes conelets called parasitic cones develop on the sice of a composite volcano as result of cracks during violent eruptions.

a

e.g. Mauna Loa. (Hawaii)

Boudary

Summary on PLATE TECTONICS

features

Examples

Bager true plate

ntal plate &

etal biate

-nad-oceanic ridge -rift valley

-volcanic activity:

mising nosaltic mayma -new oceanic crust 15

torhed

divergence between American plate ? African)

plate

aid-Atlantic Ridge is. formed

-Pake

faulting

-volcanic activity:

rising magma

divergence between African plate & pretan plate

East African Rift

valley is formed

-earthquake

-faultino

-Malamo“ɔnish.

A conservative piata margan, llora of

servatront

-fold mountain

Huolŝanic intrusion but

ng violent eruption -earthquake

sabduction of oceanic Wats and form trench Benioff Zonel

ge of oceanic plate selt into magpa -volcanic activity: „rising magna"

volcanic eruption -earthquake

-fold mountain

-transform fault

-no volcanic activity Bagarthquake,

.q. 1

collision between

Eurasian plate B ̈Indian

plate

Himalayas

R-9. 2

collision between

-Eurasian plate & African

piate

ALAB

.collision between 5.

American plate & Nazca plate

Peru-Chile Trench Andes Mountain

Pacific prate slide over Aserican plate

San Andreas Fault

Volcabulary:

core: mantle, ecounts of St. Trench, subduction, Benioff Zone, continental crust, plate tectonic, nagrayfold mountain. compression, earthquake, convection current, tension, treasform fault. Himalayas, constructive, destructive, Alps, Andes Mountain, siel soft, conservative, mid-oceanic ridge, valley.

Demand

1. The degree of necessity of the commodity

Increase in necessity - mora inelastic.

2. The possibility of substitution of the commodity

Increase in substitutability - more elastic

Individual Supply Curve

1. Suppliers are rational:

Producers respond. to change in price of a good.

{11) They tend to produce more when price o

a good goes up.

(III) They tend to produce less when price"

a good goes down.

(IV) They have a plan of production. Ceters Paribus, .e other things being constant

i. Sased on a supply schedule showing quantity

supplied at each different price, a supply curve can be drawn

3. Price of the commodity

At very high price more elastic

4. Durability of the good

Higliar durability more elastic

5. The proportion of income spent on the good

Higher proportion more elastic

6. The nature of goods (habit-forming or not!

Addictive moné inelastic:

Market

Some

Terms

Confusing

1. Joint Demand - used on demand for two

complementary goods.

Supply Curve

Contents

Factors Affecting

Supply

Supply

1. Increase in Supply

Supply curve shifted rightward and quantity supplied increased to Q1 even though price stood at Po

2. Decrease in Supply

Supply curve shifted leftward and quantity supplied decreased to O even though price stood at PQ

K

9%

1. Changes in the price of factors of

production and thus changes in cost of production

Cost increased supply decreased Cost decreased supply increased

2. Improvement in production technology and thus reduction in cost of production - supply increased

it. The supply curve slopes upwards from left to

right. This shows that a greater quantity will be offered for sale at a higher price' than at a lower price.

-

15. Individual supply is the supply of a commodity

by a single supplier

MARKET SUPPLY CURVE is the sum of the individual supply curves. It is the market supply which .determines the price in the market.

Price:

Elasticity of Supply

Qs =

Quantity Supplied

(Huasurement of responsiveness of quantity supplied to changes in price)

Es 0

(or perfectly)

aas ! f

Absolutely

Inelastic

2. Competitive Demand demand for two close

substitutes

3. Derived Demand a good is demandad.because of

its contribution to the production of another, good:

4. Composite Demand - demand for a single product:~

which can be used for two or -more purposes..

an increase in the demand fa one type of use will tend

to reduce the supply of the

product in its other uses.

5. Joint Supply two goods which are technically

connected will be produced under

one production process

Competitive Supply

increased supply of one good leads to a decrease

In the supply of another

Changes in Quantity Supplied-

Supply

Supply of a commodity is the quantity of that commodity which producers, are willing to offer for sale at different prices per unit of time, other things being constant

Changes in Supply:

Law of

Supply

The higher the price, the greater, the quantity that will be supplied, and vice versa, other things: being constant

Scoopy der Market Supply. Supplier A

Curve

Suppller H

Owing to changes in price, the quantity supplied by each producer, the market as well, will change accordingly.

It is just a description of the law of supply and. representing the movement along the supply curve only, other things being constant.

1. Increase in Price:

Price increased from Po

to P

Quantity supplied increased

From Qo, to 01.

Decrease in Price

Price-decreased from Pj

to Po

Quantity supplied decreased from 01 to 00

Care must be taken not to mix up changes in quantity supplied with changes in supply which means the deviation from the "ceteris paribus" assumption in the law of supply. It is represented by shifting the supply curve out of its original position.

B. Supply

Contents

Meaning

Relatively Inelastic

Unitarily Elastic

Es = 1

Relatively Elastic

Absolutely

(or perfectly)

Elastic

as %Qs=%s'?...

Es.1%

as X 30s %5 P..

És

(infinitivel

as % 4Qs approaches o

or % AP approaches. zero,

00.01 02.03

Factors Affecting.

Supply Elasticity

1. Excess Capacity and Stock

Higher more elastic.

2. Time periods involved or needed

Short-run more inelastic...

Long-run - more elastick

3. Availability of input

Ready in use- more elastic.