📖 Theory · Lesson 1
Energy and technology
Technology changes very fast. Many machines need energy to work. Some energy is clean (it does not make the air dirty) and some is not.
🏙️
skyscraper
a very tall building
🚁
drone
a flying machine with no pilot
📱
smartphone
a phone that is also a small computer
📲
app
a program on a phone or tablet
🌐
internet
the network that connects computers
📶
wi-fi
internet without wires
🛰️
satellite
a machine that goes round the Earth
🖥️
screen
the part of a device that shows pictures
⚡
electricity
energy that makes machines work
☀️
solar power
energy from the sun
🌬️
wind power
energy from the wind
🚗
electric car
a car that uses electricity, not petrol
🌍 Clean energy
Solar power and wind power are clean energy. It is better to ride a bike or walk than to go by car, and you should turn off your computer when you finish using it.