What are needed by living things?

What are needed by living things?
In hot weather it is very likely that your mouth and throat feel dry. You are thinking of having a glass of cold water. You are thirsty and your body needs water. All living things need water.When you dive, your body will show a reaction. Even though enough water is available, your body needs something else. It needs air. Water and air are two out of many things needed for living things to stay alive.All living things carry on respiration. To breath they need air. Air contains nitrogen, oxygen, carbondioxide, water vapor and other gasses. Without oxygen in the air, living things will die soon. Oxygen is also found in the water. Most organisms living in water get the oxygen that they need from water. Plants and animals need oxygen to get energy.Living things need air, water, space and food. Each living thing has differences for their food need, for example plants need light to get energy to produce food. You have noticed that living things grow and develop, respond to any stimulus and do other activities. Therefore, they need enough space to do such activities. To do these activities organisms need energy. Where do they get the energy from? Like cars which need fuel, living things also need fuel (energy) from the food.Questions:1. What are needed by living things?2. Why do living things need air?3. Why do living things need oxygen?4. What is oxygen?5. What does a plant need to get energy?6. What are the characteristics of a living thing?7. Why do living things need food?