1. By Michael B and Stewart G

2. Four events that have to happen in order for an engine to work  Intake  Compression  Power  exaust

3. How has the engine improved efficiency  Mechanization has helped make production of farm products possible with a great reduction in the labor required.  In 1800, about 55 worker-hours were needed to produce an acre of wheat.  In 1875, using steam traction engines and horses, about 15 worker-hours were needed.  In 1925, using early gasoline tractors, an acre of wheat could be produced in about five worker- hours. Modern machinery requires a little more than one worker-hour to produce the same acre of wheat.