Fracture motorbicycle piston was analysed by means of chemical composition analysis, hardness testing, metallographic examination, and the macro and micro-fractography analysis.
I sat down and admired the view. After a time I heard a motorbicycle start up and I saw the paperman riding off and, as I watched, I saw Mrs. N come out from behind the Mill.
、硬度测定、金相检验以
口宏、微观
车
， 我看到
走
