Across
- 3. There are volcanoes in Indonesia and ........
- 6. In 2015, we have serious air pollution called ......
- 7. ...... fires causes haze.
- 9. Wastewater from toilet is purified.
- 10. Sulfur dioxide is released from ........
Down
- 1. Smokers' lungs have this colour.
- 2. In 2015, the Pollutant Standards Index (....) is above 300.
- 4. Nitrogen oxides are produced from ....... strikes.
- 5. Incomplete combustion from cars produce this gas.
- 8. Singapore take seawater to make ..... water.