`3.`
1. cholera
2. die
3. polluted water
4. dead
5. aquatic plants
`5.`
1. If people didn’t rubbish in the street, it would look attractive.
2. If there weren’t so many billboards in our city, people could enjoy the view.
3. If there wasn’t so much light in the city at night, we could see the stars clearly.
4. If we didn’t turn on the heater all the time, we wouldn’t have to pay three million dong for electricity a month.
5. If the karaoke bar doesn’t make so much noise almost every night, the residents wouldn’t complain to its owner.
6. She wouldn’t have a headache after work every day if she didn’t work in a noisy office.
