Ex.4
1. We shouldn't pollute rivers, lakes and seas.
2. We can use water for cleaning/washing up.
3. You should't leave water/tap open.
4. People can save the Planet Earth.
5. They shouldn't have a bath every day.
6. He sholudn't throw litter into the rivers/lakes/seas.
7. Students should regularly take care and water plants.
Ex.5
1. Water isn't important for life. False
2. Lake Baykal/the Baikal is in danger now. True
3. Water isn't clean in seas, rivers and lakes. False
4. We should keep water clean and air fresh. True
5. People should help to save nature from pollution. True
6. People don't think about how to save the Planet Earth. False
Ex.6
1. deep
2. like
3. see
4. fish
5. meter
6. crystals