【简答题】Most people usually traveled by ship and train which are driven by steam engine. It played an important part in many kinds of vehicles several scores of years ago. Who invented steam engine and what u...
【简答题】Mr Ling lives in China. He worked in a factory and last year he retired. His wife died five years ago and his son works in Japan. He always has sports and he is in good health. One day his son called ...