Look at your watch for just one minute. During that short period of time, the population of the world had increased by eighty-five people. Perhaps you think 【S1】______ that isn't much. In the next hour, more than 5,000 additional people will be living on this planet. So it goes, hour after hour. In one day, there are about 120,000 additional mouths to feed. Multiply this by 365. What will happen after 100 years? 【S2】______ This population explosive may be the greatest 【S3】______ challenge of the present time. Within the next forty years, the world population may double. Can the new frontiers of science meet the needs of the crowded world of tomorrow? If the present rate of population increase continues for the next 600 or 700 years, there will be standing rooms only. Each will have between 3 to 10 square feet 【S4】______ of space in which to live. This contains the 【S5】______ mountaintops, deserts, and the ice and snow fields of the polar areas. Of course, no one expects such a thing to happen. War, plague, famine or some other catastrophe can be expected to occur long when the 【S6】______ population reaches this point. Actually, the danger is in 【S7】______ an overcrowded world where people are huddled together so that they cannot move arms and legs, but in an upset balance between population and resources. Since 600 years is so far away, take a look directly ahead. How can the hungry people be filled? About 【S8】______ half of the babies born this year will not have enough to eat. Is the world going out of water? Will there be 【S9】______ enough fuel? What will supply the energy need to run 【S10】______ the machine of tomorrow's world? Certainly, man must look to the future and find new ways of providing for his needs. 【S1】