문제 2Every day, we leave behind marks of the gases that warm our planet, much like footprints left in wet sand. These marks, often called our carbon footprint, _______________. Many students think that only large factories create these marks, but ordinary habits at home also matter greatly. For example, turning off lights when leaving a room reduces the energy that power plants must produce. Walking or biking to school instead of riding in a car also lowers the amount of gas released into the air. In contrast, leaving devices plugged in all night quietly increases our footprint without our notice. Therefore, students who practice these simple habits regularly can shrink their footprint significantly. Small daily choices, repeated over time, become powerful tools for protecting the environment we all share.