1. If people didn't throw rubbish in the street, the street would look attractive.
2. If there weren't so many billboards in our city, people could enjoy the view. If there weren't so much light in the city at night, we could see the stars clearly.
3 Many rivers and lakes are poisoned because factories produce waste and pour it into rivers and lakes.
4 A state of emergency following the earthquake has been declared by our government
5→ if you. leave the tap running while brushing your teeth , you will waste water..