The correct answers are:
- to replenish sand on a beach
- to mitigate beach erosion for a period of time
Beach nourishment is a process where sand is added to a beach to combat erosion and provide protection for coastal communities and habitats. It is not a permanent solution, but can help mitigate erosion for a period of time. It is also done to replenish sand that has been lost due to natural processes or human activities.