01.Unprecedented construction of tens of thousands of monumental engineering projectsdesigned to control floods, protect clean water supplies, and provide water for irrigation and hydropowerbrought benefitsto hundreds of millions of people.
02.Whereas prehistoric man had no exposure to urban lifestyles—the forcing house of intelligence—the evidence suggests that ants have lived in urban settings for close on a hundred million years,developing and maintaining underground cities of specialized chambers and tunnels.
03.An accident that occurred in the skies over the Grand Canyon in 1956 resulted in the establishment of FAAto regulate and oversee the operation of aircraft in the skies over the United States, which were becoming quite congested.
04.Large sample international comparisons of pupils’ attainments since the 1960s have establishedthat not only did Japanese pupils at age 13 have better scores of average attainment,but there was also a larger proportion of “low” attainers in England, where, incidentally, the variation in attainment scores was much greater.
05.In the face of the escalating perils from indiscriminate applications of pesticides,a more effective and ecologically sound strategy of biological control, involving the selective use of natural enemies of the pest population,is fast gaining popularity—though, as yet, it is a new field with limited potential.
06.However, when we look at the 100 billion stars in our galaxy, and 100 billion galaxies in the observable Universe,it seems inconceivable that at least one of these planets does not have a life form on it; in fact, the best educated guess we can make’ using the little that we do know about the conditions for carbon-based life,leads us to estimate that perhaps one in 100,000 stars might have a life-bearing planet orbiting it.
07.The antiseptic properties of tannin, the active ingredient in tea, and of hops in beer—plus the fact that both are made with boiled water—allowed urban communities to flourish at close quarters without succumbing to water-borne diseases such as dysentery.
08.If successfully implemented,proponents claim,vertical farms offer the promise of urban renewal, sustainable production of a safe and varied food supply (through year-round production of all crops), and the eventual repair of ecosystems that have been sacrificed for horizontal farming.