Tropical rain forests are:

A.The most valuable and the richest ecosystems on earth
B.They play a critical pat in the earth’s life support systems and house 50% and possibly as much as 90% of all the species on earth
C.They are a key storehouse of foods, oils and minerals and source of ingredients that make up a range of medical treatments
D.All of the above

C4 Plants means:

A.A group of plants which include maize and sorghum
B.The process of carbon fixation usually found in tropical plants with high growth rates
C.Both (a) & (b)
D.None of these

Peat means:

A.A dense accumulation of only partially decomposed plant materials which has formed in wetlands over a period of thousand of years
B.It collects in still water which does not have enough oxygen to complete the total process of decay
C.Both (a) & (b)
D.None of these

Boreal forest is:

A.The large coniferous forest areas in the northern hemisphere between the latitudes of 50
B.Large areas of boreal forest are found in Scandinavia, Siberia and Northern America
C.Both (a) & (b)
D.None of these

Acid rain means:

A.A type of pollution which washes out of the atmosphere as dilute sulphuric and nitric acids
B.It tends to be a regional rather than a global phenomenon linked to particular industrial activities and meteorological conditions
C.Both (a) & (b)
D.None of these