Thomas Malthus published his "Essay on the Principle of Population" almost 200 years ago. Ever since then, forecasters have being warning that worldwide famine was S1_____ just around the next corner. The fast-growing population's demand for food, they warned, would soon exceed their S2_____ supply, leading to widespread food shortages and starvation. But in reality, the world's total grain harvest has risen steadily over the years. Except for relative isolated trouble S3_____ spots like present-day Somalia, and occasional years of good harvests, the world's food crisis has remained just S4_____ around the corner. Most experts believe this can continue even as if the population doubles by the mid-21st century, S5_____ although feeding I0 billion people will not be easy for politics, economic and environmental reasons. Optimists S6_____ point to concrete examples of continued improvements in yield. In Africa, by instance, improved seed, more S7_____ fertilizer and advanced growing practices have more than double corn and wheat yields in an experiment. Elsewhere, S8_____ rice experts in the Philippines are producing a plant with few S9_____ stems and more seeds. There is no plant breeders can continue to develop new, higher-yielding crop, but most researchers see their success to date as reason S10_____ for hope. S1. being-been S2. their-its S3. relative-relatively S4. good-bad S5. as-去掉 S6. politics-political S7. by-for S8. double-doubled S9. few-more S10． reason- the reason
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