填空题

A problem related to the (36) for land use is whether crops should be used to produce food or fuel. Two areas will be examined in this (37) . Firstly, the problem should be viewed in its (38) perspective. When oil prices rose (39) in the 1970s, countries had to look for (40) to solve the resulting (41) . In developing countries, one of the possible answers to it is to produce alcohol from plant material. This has led to a lot of research in this area (42) in the use of sugar. The use of this material resulted from two (43) reasons: a reduction in its price and low production costs. (44) . like the sweet potato in tropical regions, and corn and sugar beet in non-tropical regions. The problem with these plants is that they are also the people’s staple food in many poor countries. (45) .farmers naturally go for what is more profitable. As a result, (46) .