1. Exhaust fumes cause a lot of ________, especially in big cities.
2. Everyone should learn to ________ ( = save) energy. Using lights/lamps only when needed is a good way to do this.
3. Nancy is ________ about pollution. This is why she walks to work instead of driving.
4. ________ is much healthier than driving, and it doesn’t pollute the air.
5. David conserves water by not letting it ________ when he’s not using it.
6. I’d like to conserve water… But I feel dirty if I don’t ________ three times a day!
7. Many unethical companies ________ their waste into rivers.
8. ________, which is partly caused by exhaust fumes from cars, is a very big problem in many big cities across the world.
9. ________ rain occurs when pollution in the air is absorbed by water droplets in clouds.
10. Oil ________ pollute sea water and kill marine life.