Нужно вставить could или should
1. You — low-energy light bulbs. 2. You — close all the doors and heat just one room. 3. Also, you — turn your heating thermostat lower. 4. You — make sure all your doors and windows seal tightly. (seal (V) – close) Feedback 4 5. You — turn off lights when you leave rooms. Feedback 5 6. Furthermore, you — look into alternative energy sources for your home.