Caves are large hollow spaces underground that take thousands of years to form.

Automatic doors are common in malls, hospitals, hotels, banks and airports.

Traffic lights help vehicles move safely on the roads.

When we see or even think about food, our brain sends signals to the salivary

The snow and ice on Mount Everest are melting due to climate change.

An escalator is a moving staircase that helps people go up and down between floors

A watershed is an area of land that catches rain or snow and drains or

Saffron is the most expensive spice. It is the stigma of the Crocus sativus flower,

Like lizards and snakes, insects are cold-blooded animals.

Since the Earth’s axis is tilted, the angle at which the sun’s rays strike the