81. Although we do not know the long-term consequences of separation or deprivation , we do know that they can produce acute immediate distress .

　　虽然我们不知道分离和丧失亲人的长期后果，但我们知道它们能立即引起剧烈的悲痛。

　　82. One can raedily trace the disappearance of dinosaurs to a major cataclysmic event .

　　人们很容易把恐龙消失的原因归结为重大的灾难性事件。

　　83. The raesons for poverty are many , but for the most part center on illiteracy , the lack of opportunities and in some cases pure laziness .

　　贫困的原因很多，但主要是因为缺少教育、缺少机会，有的情况下纯粹是由于懒惰。

　　84. Child development depends on a number of factors , both physical and psychological . Correct parental nurturing from infancy through adolescence determines both the physical and mental profile of a mature individual .

　　儿童的发展取决于很多因素，包括生理的和心理的。从婴儿期到青春期的正确的家长教育决定一个成熟的个人的体质及智力的状况。

　　85. Factors such as self-condidence and ambition , combined with determination and willpower , contribute to eventual success or failure .

　　自信、雄心，加上决心和毅力等因素是造成最终的成功或失败的原因。

(责任编辑：田学江)