At the top of a mountain, water boils at 100 degrees Celsius.

If you mix Red and Blue, you make purple.

Leonardo da Vinci invented the bicycle.

The Earth is bigger than Mars.

The first mobile phone in 1973 weighed two kilos.

If you wear dark clothes on a sunny day, you will get hotter.

Astronauts walked on the Moon for the first time in 1979.

Insects have eight legs.

Humans need more sleep than giraffes.