Why did we invite two science teachers to guide our PBL project? Our project is a compost bin, which uses fallen leaves, kitchen waste, fruit peels, etc. to create real fertilizer. However, how can we make nutrient-rich fertilizer that can help plants grow? We asked our science teachers to teach us how to set different conditions for each compost bin, some with more water, some with more leaves, etc. We will experiment and record daily to compare which method is the most suitable. Through scientific learning, we will complete our PBL project!