Unit 1 Normal knowledge Text 1 Rail transport Text 2 Train Text 3 History of railtransportation Classification yard Railroad track Railway switch Unit 2 Locomotive Text 1 Steam locomotive Text 2 Diesel locomotive Text 3 Electric Locomotive The development of electric locomotive in the world" Electric multiple unit Maglev Unit 3 Main components of electric locomotive Text 1 Bogie Text 2 Pantograph Text 3 Electrical motor Circuit breaker Transformer Coupler Unit 4 Electric locomotive power supply system Text 1 Railway electric powersupply system Text 2 Traction converter Text 3 Overhead line catenary ……
