Central bankers must learn to speak in colloquial language Many simple ones that you can start with are painting. Painting can come in a lot of forms. For the really children, they're going to love fingerpainting. Older children will like experimenting with tempra paints. Watercolors make the perfect fit for all ages as they can challenge the advanced artist and so are safe for even the toddlers. Before that, what is the nature of the enterprise itself is an issue that has been ignored by traditional microeconomic theory. In the traditional microeconomic theory, is the manufacturer's production process as a "black box", namely enterprise is abstracted into a from input to output a "black box" of the pursuit of profit maximization. High compression ratio if choose low grades of gasoline engine, can make the cylinder temperature rises, the incomplete combustion of gasoline, strong vibration machine, so that the output power down, damage to the parts, fuel consumption and driving. If lower compression ratio engine with high grade oil, can appear "delay" phenomenon, namely the compression ratio is less than the highest point of spontaneous combustion, as will appear incomplete combustion phenomenon, the engine is no good.