- Air is a mixture of different gases. One of these gases is oxygen.
- People, animals and plants need oxygen to live.
- There is water in the sea, in rivers, in lakes and in clouds.
- Sea water is salty. You cannot drink it. You cannot water plants with it.
- There is fresh water in rivers and lakes. You can drink it. You can water plants with it.
- Water is a liquid. Water vapour is a gas. Ice is a solid.