【单选题】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...
A.
James Watt invented the steam engine
B.
James Watt first used horse-power as a unit of measure
C.
how much power does a horse have
D.
why Wat t ’ s engine is called a ten horse-power engine
【单选题】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...