This can be very the same as the recycling challenge, only this is for picking up any litter you see lying around. I don't know if this could fall under #31. Alternatively, one could add to the instructions of the Recycling challenge that picking up any litter you encounter on your daily travels also counts.
This can be very the same as the recycling challenge, only this is for picking up any litter you see lying around. I don't know if this could fall under #31. Alternatively, one could add to the instructions of the Recycling challenge that picking up any litter you encounter on your daily travels also counts.