1. Types of sources of energy:
Solar energy, wind energy, light energy, nuclear energy, electrical energy, thermal energy,...
2. Give examples (wind energy):
During daylight hours, air above land heats up more quickly than air over water. Air over land expands and rises as it heats up, and and heavier, cooler air flows in to take its place, creating wind. At night, the winds reverse direction. Similarly, the atmospheric winds that circle the Earth are created because the land near the equator is warmer than the land near the poles. Wind power, captured by windmills (often in large arrays) is used mainly for electricity generation
3. To save energy, we should:
+ Turn off the lights and fans when we go out
+ Use electricity efficiently
+ Use public transports instead of private transport
+ Use low energy light bulbs