How to make an ultra-simple water rocket?

Preparation materials: mineral water bottle, knife, valve, adhesive tape, tail wing and rubber cap.

1. Cut the tail of one of the mineral water bottles with a knife, as shown in the figure below.

2. Wrap two mineral water bottles together with adhesive tape, as shown in the figure below.

3. Stick the tail wing on the mineral water bottle, as shown in the figure below.

4. Continue to wind the tail wing with adhesive tape, as shown in the figure below.

5. Fix the rubber cap on the bottle with adhesive tape as shown in the figure below.

6. Remove the bottle cap, and then put on the valve, as shown in the figure below.

7. As shown in the picture below, the water rocket is ready.