2. ++Save money ﹏ the material we used were recycled one. ++Convenient ﹏ we do not need to look after it when heating the water. ++ Protect the environment ﹏ the solar cooker use solar energy which is renewable energy. It reduces the need to use coal, petroleum gas.. etc which are non-renewable energy. In so doing can reduce the amount of pollutants. ++Creative ﹏ the solar cooker is made from the ideas of the whole group.

3. 。 A paper box 。 A paper which is black in colour 。 Aluminium foil 。 Cling wrap 。 Cotton 。 An aluminium can

6. → We used a box and painted it black. → Inside the box, we glued aluminium foil onto it. → We made two cards for reflecting light on two sides of the box. → We put the can in the middle of the box and use a convex lens to focus light onto it. → And then we cover the box with cling wrap.

7. ∠ Black surface can absorb energy more efficiently. ∠ Silvery surface inside the box can reflect energy onto the can. ∠ Cotton was wrapped around the can to reduce the energy loss. ∠ The cling wrap can have greenhouse effect to decrease the energy loss. ∠ Convex lens is used to focus the energy onto the can.

8. The first test: Original temperature~20 o C 1st~21 o C 2nd~22 o C 3rd~22.5 o C 4th~23 o C o C 5th~23.5 o C 6th~24 o C 7th~25 o C 8th~26 o C 9th~26.5 o C The second test: Original temperature~22 o C 1st~23 o C 2nd~25 o C 3rd~27 o C 4th~30 o C 5th~30.5 o C 6th~31 o C 7th~32 o C

9. ∞We have leant how to apply the knowledge we had leant before and apply these to our daily lives. ∞We learned the principle of keeping thing warm. ∞We learned how to use our renewable energy-solar energy. ∞If the society makes use of solar energy, it can help reduce a lot of pollutants.

10. ↑ We should use more reflecting surfaces to reflect energy onto the can ↑ We should put the can higher in the box. ↑ We should use a bigger paper box. ↑ The aluminium foil should be straight so as to cause regular reflection.

11. ╭☆ Ching Man Ka (7) ╭☆ Ho Pui Ki (10) ╭☆ Lee Cheuk Man (13) ╭☆ Yau Yuen Ching (17) ╭☆ Yeung Ka Hei (18)

12. Paper in Black $1 Paper box free Aluminium foil $12.3 Cling wrap $15.4 Cotton free Convex lens free Can free