The science subject I want to talk about my natural science course in high school. Properly speaking, that's a practical lesson about planting vegetables with Hydroponic method, do you know hydroponic? I was planting vegetables, lettuce, by using the hydroponic system at the school garden. The hydroponic system is composed of water pipes, and the water flows through it, It's not traditional in the soil. We didn’t use any chemicals, so there were a lot of pests on the leaves. We need to wash and against them. Finally, after 6 weeks, we harvested it. it’s fresh, better than the one we usually buy in the market, because it’s green health product. I try to find materials to install the system, but it’s difficult to finish. Then we made a presentation to show our achievements.