Read the text and fill in the gaps with the right phrases.

What Is Ecology
No living thing or group of living things ... . All organisms, plants and animals ... and all species of living things ... . Ecology is a science. It studies how plants, animals and human beings live together and influence each other. It is also a science about our environment. People have always studied living things ... . In other words, they have always studied the air, the water, the soil and all other things that are around a person, animal or plant. The environment can influence ... and the way they develop. Ecologists also study what happens to different species, how they change. The scientists collect information about the number of living things in different areas, ... . Ecology is one of the most important sciences in the 21st century. It teaches us how to survive in the modern world.