Answer:
preservation of raw materials
Step-by-step explanation:
Reusing and recycling is the process by which the used products are used again or recycled in different form to use it again. Excessive use of the raw materials can lead to their extinction. Recycling the materials helps in decreasing the pollution in the environment. It also helps in reduction in the emission of the harmful gases. When municipal wastes are reused or recycled, the raw materials are preserved. These are the process involved in sustainable use of resources.