The correct choices are;
People adapt to their environment.
People adapt their environment.
Changes to the earth's environment can be harmful.
Changes to the earth's environment can be beneficial.
When we discuss our environment we mean the world in our general surroundings which can influence our lives.
When we discuss the environment we mean the world in our general surroundings that encompasses and influences all life on earth, including the air, natural ways of life, the water cycle, plants, creatures and different people.
Environmental change is one of the huge natural changes that is influencing the lives of individuals, creatures and plants everywhere throughout the world.