Studies show that changing 45 minutes of exercise on an electric treadmill to jogging in a nearby park can reduce carbon dioxide emissions by nearly 1 kilogram. Without washing machines to dry clothes, let them dry naturally, which can reduce 2.3 kilograms of carbon dioxide. Emissions; U. S. computers and their monitors can reduce the carbon dioxide emissions of these computers by one-third during lunch breaks and after work; change to water-saving showerheads, which not only save water, but also enable hot shower The resulting CO2 emissions are cut in half. What does the author most likely want to express through this text? ['Natural lifestyles save energy.', 'Energy saving awareness is important.', 'Ordinary people can contribute to energy savings.', 'Energy saving must start from little by little.']