Exercise 5. Complete the sentence with the words in the box.
- Untreated or wastewater should be treated before it is discharged into the river or ocean.
- More and more waste and pollutants are poured into the water, the soil, and the air.
- The radioactive material is stored in a special radiation-proof container.
- Oil spills can cause the death of aquatic animals such as fish.
- Untreated sewage can spread disease and contaminate drinking water sources.
- Cholera is transmitted through contaminated water.
- The health effects of air pollution include heart disease, lung cancer, and asthma. (Note: "effects" could be a more appropriate term for health impacts, but "poison" fits the context here in a broader sense if considered as harmful substances.)
- Carbon dioxide is a dangerous air pollutant.
- Over 150,000 tonnes of waste are dumped annually along the coastline. (Note: "contaminated" seems more suitable in the context of specific pollution, but "dumped" is common for waste.)
- Up to 100,000 fish were found dead along the river last week.
Exercise 9. Choose the correct word A, B, C, or D for each gap to complete the following passage.
Rivers are (1) C. among of the world’s most important natural resources. Many cities are on large rivers, and (2) C. almost every country has at least one river that (3) D. plays an important part in the lives of its people. Besides transportation, rivers (4) B. provide food, water for crops, water to drink, and opportunities for recreation for people who live along their (5) A. banks. And in order to get water for crops, engineers sometimes build a dam across a river and let the water become a lake (6) B. on the dam. Then people can use their water not only to (7) B. irrigate fields but also to make electricity for homes and industries. (8) D. However, the water often becomes polluted when cities on river banks grow (9) A. in size and the number of industries increases. We are learning that it is necessary to (10) D. maintain rivers clean if we want to enjoy the benefits of natural resources.