In the northern winter, two well- defined low pressure cells are centered respectively on the North Atlantic Oceans because?

A. the sea is relatively warmer than the land

B. there are warm ocean currents

C. the northern parts of the oceans are shallow

D. the seas are swept by strong winds

Planetary winds are deflected on crossing the Equator due mainly to the effects of?

A. Coriolis force

B. Ferrel's law

C. the jet stream

D. gravitational force

Which savannah vegetation is characterized by grasses of about one metre high and scattered trees with flattish canopy?

A. Sahel

B. Sudan

C. Guinea

D. Derived

The process by which materials are physically transferred from one soil layer to another is called?

A. leaching

B. physical weathering

C. illuviation

D. eluviation

The most important environmental resources that sustains natural processes in an ecosystem is?

A. light

B. water

C. air

D. energy

Nutrients lost by trees in leaf-fall can be re-used by the trees because the?

A. trees are renewable resources

B. nutrients circulate in the ecosystem

C. nutrients are inexhaustible

D. trees store nutrients

Which of the following human disease is often heightened by the introduction of irrigation farming in an area?

A. Bilharzia

B. Dysentery

C. River blindness

D. Cholera

One serious environmental hazard which may result from the destruction of the zone layer is?

A. flooding due to melting of snow

B. pollution of rain water

C. increase in atmospheric temperature

D. decrease in the quantity of oxygen in the atmosphere

Dense population mainly dependent on peasant farming is found in?

A. Witwatersrand in South Africa

B. the coastal areas of WestAfrica

C. the Rwanda-Burundi area

D. the Katanga District

Rapid population growth is mainly the natural consequence of?

A. low fertility and morality

B. rapid economic development

C. high fertility with high morality

D. low morality with high fertility