Air conditioning, or cooling, is more complicated than heating. Instead of using energy to create heat, air conditioners use energy to take heat away. The most common air conditioning system uses a compressor cycle (similar to the one used by your refrigerator) to transfer heat from your house to the outdoors.
Picture your house as a refrigerator. There is a compressor on the outside filled with a special fluid called a refrigerant. This fluid can change back and forth between liquid and gas. As it changes, it absorbs or releases heat, so it is used to “carry” heat from one place to another, such as from the inside of the refrigerator to the outside. Simple, right?
Well, no. And the process gets quite a bit more complicated with all the controls and valves involved. But its effect is remarkable. An air conditioner takes heat from a cooler place and dumps it in a warmer place, seemingly working against the laws of physics. What drives the process, of course, is electricity — quite a lot of it, in fact. Hope this helps?
I would have to say it would be a PDA, because they generally arent much bigger than a cell phone. at least mine is pretty small anyway. there are certain brands that make larger ones almost the size of a tablet, but in general terms, PDAs are usually pretty small. hope this helps.
Answer:
Retailing.
Explanation:
La venta al por menor o retailing es el suministro de bienes físicos a los consumidores para uso personal, sea en pequeña o grandes cantidades, siempre que esté destinado a consumidores finales. Es un sector que consta de diferentes ramas (como la industria alimentaria, la industria de la moda, la industria del mobiliario para el hogar, etc.). El comercio minorista es el último eslabón de la cadena de suministro que va desde el fabricante hasta el consumidor.
