The International Space Station
The International Space Station is a man-made object that orbits the Earth at an altitude of about 400 km. It serves as a laboratory for scientific experiments in many fields.
Cities
A city is a place where thousands or even millions of people live together in a small space. Cities are much larger and more important than towns or villages. Today, about more than half of the world’s population live in cities. Contents of this module (32 pages) Preview the whole module