2、 The word ( ) itself usually refers to the deterioration of metals and ceramics, while similar phenomena inplastics generally called ( ) C.degradation...corrosion D.corrosion... degradation

问答题2、 The word ( ) itself usually refers to the deterioration of metals and ceramics, while similar phenomena inplastics generally called ( ) A. recrystallization.... corrosion B. recrystallization...deg

问答题Before two components are assembled together, the relationship between the dimensions of the mating1.surfaces()A. must be giving outB. should printed clearlyc. must be specifiedD. should be clearl