stress, strain: are the most comprehensive terms and apply to a force tending to deform a body: the weight of the snow put ~ on the roof; bolts snapping under the tremendous ~ of the impact.          表示心理压力时用stress，如stress management (=dealing with stress) 压力管理，如stress is often a factor in the development of long-term sickness心理压力常常是形成长期病的一个因素, she failed to withstand the stresses and strains of public life她承受不了公众生活的紧张压力，under the stress of poverty在贫困的压力下，这个词还表示强调=emphasize     deform畸形，指由于受压力或损伤而改变形状外观  


pressure: commonly applies to a stress characterized by a weighing down upon or a pushing against a surface: normal atmospheric ~.    (又如how can anyone enjoy the pressures of city life怎么会有人喜欢都市生活的压力呢，这个词可以做动词，表示催促劝说施压，如he will never pressure you to get married他永远不会催促你结婚，如don't let yourself be pressured into making a hasty decision不要勉强自己仓促作出决定)


tension: applies to either of two balancing forces causing or tending to cause elongation of an elastic body OR to the stress resulting in the body: tested the ~ on the tightrope.    elastic: 可拉伸而不断   表示关系紧张时用这个词，如there is mounting tension along the border边境局势日趋紧张，如international/racial/political tensions国际紧张局势/种族间的紧张关系/政治上的紧张状况


stress, strain压力张力: 泛指使物体变形的力，pressure压力: 指作用于表面的重力或推力，tension张力: 指使物体伸长的两个力，或物体内的拉紧状态


记忆方法: 1）首字母SSPT甚是普通人人都有<==压力

         2）压力的意思是作用于物体的力mean the action or effect of force exerted upon or within a thing.