Let us consider what science and technology have to contribute to the food problem. The simplest way to increase food production, one might suppose, is to bring more land 【C1】______ cultivation and put more people to work on it. Some of the underdeveloped countries have resorted to this 【C2】______ approach, without notable success. It contains several fallacies. For one thing, it usually means 【C3】______ into marginal lands where the soil and climatic conditions give a poor 【C4】______ . Cultivation may quickly deplete this soil,【C5】______ it for pasture or forest growth. It is often possible, of course, to turn such lands into useful farms by agricultural 【C6】______ for instance, a sophisticated knowledge of how to use the available water【C7】______ an irrigation system may reclaim semi-arid grasslands for crop-growing. But the cultivation of marginal lands i6 in any case unsuccessful【C8】______ it is carried out by farmers with a centuries - old tradition of experience or by modern ex pelts with a detailed knowledge of the【C9】______ conditions and the varieties of crops that are suitable for those conditions. Such knowledge is【C10】______ absent in the underdeveloped countries. 【C11】______ , we know that highly developed countries have not increased the【C12】______ of acres under cultivation, 【C13】______ on the contrary have 【C14】______ their marginal lands and steadily reduced the proportion of the population engaged in farming. Efficient farming【C15】______ concentration on the most efficient lands, and it results in greater production with【C16】______ people. The problem of the underdeveloped countries, then is to increase the【C17】______ of their farms and farmers. This would allow them to industrialize and to feed their people more adequately. It is not easy to【C18】______ , how ever. The farmers are conservative and resistant to change【C19】______ their methods of cultivation. The underdeveloped countries are greatly in need of studies and experiments to help them to【C20】______ modern agricultural methods to their own conditions. 【C1】