Correct Answer: D. Earth

Correct Answer: B. deposition of a large volume of materials on the level of plain

Correct Answer: A. constant high temperature

Correct Answer: D. stalactites

Explanation

(a) Description of Stages of Development of a River

Upper course / Torrent stage / Youthful stage

— This section or stage of the river occurs near the source of mountain area.

— The river flows swiftly as it descends the slope of the mountain.

— The river is very active in vertical corrosion

— Down cutting of the river bed occurs more rapidly than lateral erosion The main features produced include river capture, narrow steep-sided (v-shaped), valleys, rapids and waterfalls, potholes, interlocking spurs gorges, plunge pools, etc.

Middle Course / Valley Course / Maturity Stage

— It has a gentle gradient

— It widens its valley

— lateral erosion becomes dominant

—The velocity is reduced due to the reduction of gradient.

— Transportation of the river's loads is more in the form of suspension and solution.

— Deposition begins to take place at valley sides and floor.

— The main features produced are wide floodplain, levees, delta, braided stream, -Ox-bow lakes, etc.

(b)Importance of Rivers to Man

— Medium of transportation

— Generation of hydro - electric power (H. E. P)

— Water for irrigation purposes

— Water for domestic purposes e.g Washing, cooking, drinking, etc.

— Water for industrial uses

— Fertile soil for agricultural activities

— Used as political boundaries for towns, states nations

— Source of fish

— For recreation

— Source of minerals e.g alluvial gold, diamond, etc.

Correct Answer: C. Shallow

Correct Answer: C. novermber to january

Correct Answer: D. concentration of industries

Explanation

Inter-ethnic war, Arab slave trade and tsetse fly infestation will lead to a decrease in population but concentration of industries would rather increase the population

Explanation

(b) Methods of mining gold in South Africa

i. Shaft/Underground method.

(1) Involves underground quarrying

(2) Vertical holes are dug from the gold seam. (3) Gold bearing rocks are broken with explosives.

(4) Gold bearing rocks are taken through conveyor belts.

(5) The rocks are crushed and treated with chemicals to obtain Gold.

(6) Sent to smelters for further refining.

ii. Planning method.

(1) Used to recover gold from river alluvium

(2) Can be an individual.

(3) The materials needed are calabashes and pans.

(4) Sand bearing gold is collected from

river bed along with some water.

(5) The container is turned round and round. (6) The gold sinks to the bottom of the container.

(7) The useless sand on top us to collect the gold.

iii. Open cast method:

(1) Used where seam is close to the surface.

(2) removal of overburden.

(3) Explosives used to break the gold bearing rocks.

(4) The rocks are loaded on trucks with shovels.

(5) The rocks are taken to the crushing mill for extraction/concentration.

(c) Importance of gold mining to South Africa.

(i) Revenue to the government. (ii) Provision of employment. (iii) Provision of social amenities.

(iv) Foreign exchange earnings. (v) Provision of gold for ornament. (vi) Provision of gold as bullions for international currencies.

(vii) Income to workers.

(viii) Skill acquisition.

(ix) Raw materials for ancillary industries. (x) production of geological maps.

(xi) Attraction to great international investments.

(xii) Development of infrastructure In the mining areas.

(xiii) Improved standard of living.

(xiv) Uranium, a bye-product of gold mining is obtained and power.

(xv) Provision of valuable goods, e.g. necklace, earrings, etc.

Correct Answer: C. ozone layer depletion