36。In l664 the great English diarist，John Evelyn，published，with the approval of the Royal Society of London，a book Sylva or a Discourse1 of Forest Trees in which one sees，perhaps for the first time，a realization2 that trees，then so important in the construction of ships，were indeed becoming sadly depleted3 and that something urgently needed to be done by way of deliberate planting to ensure enough for the future.
1664．年，英国伟大的日记作家JEvelyn，经伦敦皇家掌握批准出版了一部森林志，即《林木论》。在这本著作中，大家可以说是首次获悉一个现实：当时，在造船业中这样要紧的树木的确正在悲惨地遭到浩劫；需要采取紧急手段，通过认真植树以便确保将来有足够的树木。
37．As a magnetic material becomes more and more magnetized，more and more of its magnetic domains4 line up，with their north poles a11 pointing inone direction and their south poles in the opposite direction．
伴随材料的磁性变强，材料中愈加多的磁畴便会排列起来，其N极均指向一个方向， 而S极则指向相反的方向。
38．Since the earth is slightly flattened5 at its poles，the distance of its surface at the north pole or south pole from its center is less than that at the equator．
因为地球的两极略为扁平，所以南北两极地表面离地心的距离比赤道地表面离地心的距离要近一些。
39．Solar energy seems to offer more hope than any other source of energy，particularly since those areas most in need of water lie rather close to the equator and have a relatively6 clear atmosphere．
太阳能好像比任何其他能源更有期望，特别是由于这类迫切需要水的区域离赤道非常近，那里有较清洗的大方。
40．For a very long time man has been seeking the possibility of combining various metals into alloys7 with a view to obtaining better materials for given purposes．
长期以来，大家一直在探寻把各种金属熔成合金的可能性，其目的在于为某些作用与功效获得更好的材料。
41．It means reorganising them on democratic lines，with governing boards made up of workers and technicians from the trade unions concerned，loyal to the concept of nationalisation as a force for social changes and operating their industry according to anational plan arrived at democratically by the community as a whole．
这意味着：要以民主的方法，由有关工会的工人和技术员所组成的管理董事会来改组各项工业。这类工人和技术员作为社会改革的一支力量要忠实于国有化这一观念，同时他们需要根据由作为整体的社会用民主办法拟定的全国性计划来管理各工业。，得出等。句中arrived at．．．whole是过去分词短语作定语修饰plan。)
42．Thirty-five seconds into the flight，with the solid rockets pumping out maximum power，Challengerlike all its predecessorswas undergoing severe aerodynamic stress．
挑战者号在其固体燃料助推火箭发出最大推力的推进下，飞行了35秒后，同以前的航天飞机一样，正在承受着巨大的空气动力的重压。
43．A gas，such as steam in the cylinder8 of asteam engine，has neither deftnite shape nor definite volume-it changes its sshape and also its svolume with change in the shape andvolume of the container．
气体，比如蒸汽机汽缸中的水蒸气，既无肯定的形状，也无肯定的体积。气体的形状和体积是伴随容器的形状和体积的改变而变化的。
44．Their wide use in industry is due not only to these properties but to the fact that the common metals can be shaped into required objects by deformation9 and by casting into mold，and to thefact that their properties can be greatly altered by alloying with other metals．
金属在工业中之所以得到广泛的应用，不止是因为它们具备上述这类性能，而且还因为普通的金属可以通过加工和铸造而形成所需要的制品，同时还因为金属的特质可通过与其他金属熔成合金而显著地改变。
45．Newton generalized the idea by supposing that any two particles in the universe gravitatetowards each other with a force varying inversely10 as the square of the distance between them and directly as the product of their masses．
宇宙中任意两个质点均以某种力在相互吸引，该力与两质点之间距离的平方成反比，而与它们水平的乘积成正比，牛顿就是通过这一假设概括了这种思想。
