n wears away metal in the moving parts，which shortens their working life.
運動部件間的.摩擦力使金屬磨損，這就縮短了運動部件的使用壽命。
2、There + be句型中的限制性定語從句漢譯時往往可以把主句中的主語和定語從句溶合一起，譯成一個獨立的句子。這種譯法叫做溶合法，也叫拆譯法。例如：
（1）There are bacteria that help plants grow，others that get rid of dead animals and plants by making them decay，and some that live in soil and make it better for growing crops.
有些細菌能幫助植物生長，另一些細菌則通過腐蝕來消除死去的動物和植物，還有一些細菌則生活在土壤裡，使土壤變得對種植莊稼更有好處。
（2）There is a one-seated which you could learn to drive in fifty minutes.
有一種單座式汽車，五十分鐘就能讓你學會駕駛。