Ch.3 Key notes

p.16
1.
In summer, he cooled the bed with a fan. In winter, he warmed the bed for his father with his body heat.

He cooked with firewood and lit up the room with an oil lamp.

p.16
2. May and her family use an air-conditioner in summer and an electric heater in winter. They cook with a gas stove and get light from an electrical lamp.
Modern life has all kinds of facilities.

p.17
1. We need to climb/ walk down the stairs.
2. We cannot iron our clothes.
3. The ice lollies will melt. The power cut may encourage bacteria to grow too.
4. We will feel hot.

p.18
LPG= Liquefied Petroleum Gas

Coal
1. From the dead plants, they form the coal layers (it takes a very long time for the layers to be formed)
2. Mine workers mine.
3. We burn coal to get energy (e.g. heat to cook food when we do barbecue)
4. Burning coal can bring exhaust fumes.

Petroleum 
1. From the dead sea animals
2.Their bodies lay at the bottom of the sea and become organic mud
3. Petroleum forms because of high temperature, pressure and compression
4. The drill extracts and refine petroleum to produce different fuel
5. The reserve can only last for 30 years.

p.20
Some appliances use more electricity, so the bill is more expensive.