2. There are so many billbords in our city. People can not enjoy the view 
If there weren't so many billboards in our city, people could enjoy the view 

3.There is so much light in the cityat night.We can not see the stars clearly.

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

4..We turn on the heater all the time. We have to pay three million dong for electricity a month.

If we didn't turn the heater all the time , we would pay three million dong for electicity a month.

5.The karaoke bar makes so much noise almost every night. The residents complain to its owner.

If  the residents complained to its owner , the karaoke bar wouldn't  make so much noise almost every night

6.She has a headache after work every day.She works in a noisy office.

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