According to the passage, damage to Afghanistan's natural environment will have a minor impact compared to other factors
can be easily corrected
has been entirely caused by returning refugees
will hinder future progress
and how to protect it are fully understood by the population
The author states that, as a result of environmental destruction the irrigation canals are presently being fully rebuilt
about a quarter of Afghanistan's evergreen forests have been destroyed
there are no forests left in Afghanistan
less than ten percent of Afghanistan's pistachio forests in the north are left intact
one million Afghan refugees have been unable to return to their homes
Mr Nuristani believes that people's ignorance is due mainly to a quarter of a century of unceasing war
makes it difficult for him to carry out his recovery program
is one of the reasons for the environmental damage in Afghanistan
can only be overcome by providing them with sufficient education
turns life in Afghan cities into a mess
199 AQUACULTURE The growing of plants and animals on land for food and other products is agriculture. Raising animals and plants in the water is aquaculture. Practised since ancient times in many parts of the world, aquaculture embraces such diverse activities as the Chinese tradition of growing carp in ponds, the harvesting and processing of seaweed in Iceland and the artificial culture of pearls - a Japanese invention. Aquaculture can take place in still water or running water, fresh water or salt water. The practice of aquaculture has been growing rapidly. Experts have projected a five-fold increase in harvests during the final quarter of the 20th century. In the 1970s, Asia accounted for approximately 85% of world production in the field. Aquaculture is regarded as one possible solution to the world's food supply problems. The quantity of tillable land is limited and shrinking everywhere. But two thirds of the globe is covered with water, and the supply of food animals and plants that may be grown there is almost limitless. In contrast to agriculture, which is practised on the land's surface only, aquaculture is three-dimensional. Within the same vertical region, several different crops can be grown at once - near the water surface, on the bottom, and in the area between. Multiple cropping of this kind, called polyculture, represents an efficient use of labour, materials and energy. Moreover, aquaculture is less affected by climatic change - droughts, floods, and extremes of heat and cold - than is agriculture.
