sentence: First of all , travelling by car is more expensive than travelling by public transport ; cars have to pay for gas , insurance , repairs , environment fees etc ; travelling by public transport is more ecological and cheaper .
modified: First of all , travelling by cars is more expensive than travelling by public transport ; cars should pay for gas , insurance , repairing , environmnet fees etc ; travelling by public transport is more ecological and cheaper .
transformation: NOUN:NUM, VERB, MORPH, SPELL