7 

1 Water pollution is the leading worldwide cause of deaths and diseases.

2 More than 14,000 people die every day by water pollution. 

3 25% of the water in the cities of China is polluted. 

5 Volcanoes, algae blooms, storms, and earthquakes.

8

1 I wouldn't have got wet if I had had an umbrella with me.

2 Unless you leave me alone, I will call the police.

3 If the weather wasn't snowy, we would go to school.

4 If it hadn't been for Jack's help, I wouldn't have been able to move the table.

5 If you doesn't drink much coffee, you can sleep.

6  If you make me some coffee, I will give you one of my biscuits.

7 Unless you had told me about Sue's hair, I wouldn't have noticed.

8 Should you see Peter, tell him he should be here at 8.00.

9

1 If he didn’t have to study for his exam, he could go out.

2 If she weren’t lazy, she could pass the exam.

Ex7:

1. Water pollution.

2. More than 14000 people.

3. 90 percent.

5. Natural phenomena.

Ex8:

1. I wouldn't have got wet if I'd had an umbrella with me.

2. Unless you leave me alone, I won't call the police.

3. If it didn't snow, we could go to school.

4. If Jack hadn’t helped me, I wouldn’t have been able to move the table.

5.  If you drink less coffee, you’ll be able to fall asleep.

6. If you make me some coffee, I'll give you some sweet.

7. Unless you had told me about Sue's hair, I wouldn't have noticed her.

8. Should you see Peter, tell him he should be here at 8.00.

Ex9:

1. If he didn't have to study for his exam, he could go out.

2. If she weren't lazy, she could pass the exam.