Read the following passage and answer the questions given after it.

Throughout the extensive areas of the tropics the tall and stately primeval forest has given way to eroded land, scrub, and the jumble of secondary growth. Just as the virgin forests of Europe and North America were laid low by man’s improvidence, so those of the tropics are now vanishing only their destruction may be encompassed in decades instead of centuries. A few authorities hold that, expect for government reserves, the earth’s great rain forest may vanish within a generation. The economic loss will be incalculable, for the primary rain forests are rich sources of timber (mahogany, teak) and such by-products are resins, gums, cellulose, camphor and rattans. No one, indeed can compute their resources, for the thousands of species that compose the forest cover, there are only a few whose physical and chemical properties have been studied with a view to commercial use.

Most important of all, the primeval rain forest is a reservoir of specimens, a dynamic centre of evolution which the rest of the world’s plant life has been continually enriched with new forms. These extensive reserves must be defended from the acquisitive hand of man, whose ruthless axe would expose them to the ravages of sun and rain.