[单项选择]There will be a steady trend toward vegetarianism. A given quantity of ground can provide plant food for man or it can provide plant food for animals which are later killed for meat. 　　In converting the tissues of food into the tissues of the feeder, up to 90 per cent is used for reasons other than tissue maintenance and growth. This means that one hundred pounds of plant food will support ten pounds of human tissue―while one hundred pounds of plant food will support ten pounds of animal tissue, which will then support one pound of human tissue. In other words, land devoted to plant food will support ten times as many human beings as land devoted to animal food. 　　It is this (far more than food preferences or religious directions ) that forces overcrowded populations into vegetarianism. And it will be the direction in which the United States of 2001 will be moving―not by presidential order, but through the force of a steady rise in meat prices as compared with other kinds of food. 　
A. rapid increase in farmland yields.
B. growing diminution of grassland.
C. gradual termination of meat supply.
D. violent struggle for animal food.

[单项选择]There will be a steady trend toward vegetarianism. A given quantity of ground can provide plant food for man or it can provide plant food for animals which are later killed for meat. 　　In converting the tissues of food into the tissues of the feeder, up to 90 per cent is used for reasons other than tissue maintenance and growth. This means that one hundred pounds of plant food will support ten pounds of human tissue―while one hundred pounds of plant food will support ten pounds of animal tissue, which will then support one pound of human tissue. In other words, land devoted to plant food will support ten times as many human beings as land devoted to animal food. 　　It is this (far more than food preferences or religious directions ) that forces overcrowded populations into vegetarianism. And it will be the direction in which the United States of 2001 will be moving―not by presidential order, but through the force of a steady rise in meat prices as compared with other kinds of food. 　
A. vegetarianism is the natural result of people’’s food selection.
B. present farmland produces more vegetables than animal food.
C. vegetarianism is to be caused by the laws of market economy.
D. people’’s food preferences conflict with supply and demand.