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1.  if teachers teach environmental issues at school, students wil be more awarer of protecting.....

2. if light pollution happens, animals will change their behavior patterns

3. if we switch from nuclear power to renewable energy source, the level of radioactive pollution decrease

4. if the water temperature increases, some aquatic creatures will be unable to reproduce

5. if the water is contaminated, people will get more diseases

write

1. if there weren't so many billboard in our city, people could enjoy the view

2. there weren't so much light in the cỉty at night, we could see the stars clearly

3. if we didn't turn on the heater all the time, we didn't have to pay 3 million dong for electricity a month 

4. if the karaoke bar didn't make so much noise almost every night, the residents wouldn't complain to its owner 

5. if she didn't work in a noisy office, she wouldn't have headache after work every day