Meanwhile world population is spiraling upward, and the most rapid increases are being made in just those regions where getting proper nourishment is the greatest problem. Today while the people of the "have" countries are well fed and are piling up surpluses of foodstuffs, in the "have-not" countries more millions than ever are going hungry every day.
In recent years, however, there has been a great "awakening of the common man." People who previously had little contact with the outside world have begun to rub shoulders with people from other, better-developed countries.
They have begun to realize, as an expert puts it, that "poverty is not a God-given state of life." Moreover, the "have" nations of the world have began to realize that no single nation, however prosperous, can exist for itself alone. The entire world is so bound together today by ties of trade and travel that poverty and famine anywhere threaten the richest of the nations along with the poorest. As a result, much thought and skilled effort are being devoted to improving food supplies in the underfed areas.
Many of the world's food problems are quite evident and can be attacked directly. Some farmers are still using tools and methods dating back to prehistoric times, you may say. Bring their methods up to date with modern tools and machines, teach them to fertilize and irrigate their soil, provide them with good seed and good animals to raise, and they soon will be producing plenty for themselves.
This approach is being followed; the agronomist in Greece, the farm expert in Afghanistan, and many others are doing all they can to improve agricultural techniques in countless widely scattered farm communities. But behind every problem that can be solved by machinery or a packet of seed or a sack of fertilizer looms a human problem having to do with what has long been known as social lag.
Whenever you try to revolutionize the ways of a people, you run into a maze(错综复杂的曲径) of intricate, interlocked problems. The behavior. of human beings is complex and cannot be controlled as simple as the behavior. of white mice in a laboratory. What seems an obvious solution may prove difficult, even impossible, to carry out.
The solution to the world's food problems depends on ______.

A. modern methods of farming
B. providing family farms
C. solving problems besides growing food
D. the help of "have" countries