对于约20美元, 您可以建立一个非常好的抛光铝抛太阳灶.

For about $ 20, you can build a very nice polished aluminum parabolic solar cooker.

太阳灶烧食物是在一个低的温度下,需要一个长的时间.

Solar ovens cook food at low temperatures over long periods of time.