sentence: In big cities , the air is very polluted because there are too many cars . Travelling by public transport reduces the impact on the environment , something that most people are aware of , but still they prefer to use their own vehicle .
modified: In big cities , the air is very polluted because there are too many cars . Travelling by public transport lowers the impact on the environment , something that most people are aware of , but still they prefer to use their own vehicle .
transformation: VERB