For many years the earth has been unable to provide enough food for these rapidly expanding populations and the position

问题描述:

For many years the earth has been unable to provide enough food for these rapidly expanding populations and the position is steadily deteriorating since the fertility of some of our richest soils has been lost and vast areas that were once fertile lands have turned into deserts.

多年来,地球已经无法为这些迅速扩大的人口和地位正在不断恶化,因为我们的最肥沃的土壤的肥力一些已经遗失,被广大地区的肥沃的土地变成沙漠有足够的食物进入