Answer:
Materials: 2 one or two liter bottles and caps, Duct tape, Hot glue gun, Half inch wide nail, Ruler.
Instructions: 1. Peel the paper off the bottles and rinse them out. 2. Screw the caps off the bottles and puncture a half inch wide hole in the center of each, using the nail. Use the ruler to check the length of each hole. 3. Position the caps so that the holes are touching each other and glue together using a hot glue gun. Add some glue around the edge where the two caps meet, and be sure to add a generous amount. This seals the caps together. If you don't have a glue gun, duct tape the caps firmly together in the same position as if you were using glue. 4. Fill one bottle two thirds of the way with water, then screw on the double cap. Take the other bottle and screw it on to the other side of the double cap. 5. Circle duct tape fully around the caps only to further seal it, even if you did already if you didn't have a glue gun. 6. Flip the bottles upside-down so that the one with the water is on top. Hold the one with the water and quickly move it in a circular motion for a few seconds. You will see some bubbles rise to the top, and then a brilliant funnel will form. Happy tornado-ing!