What of the following refers to hypotheses which are confirmed by varied tests?

Who invented the mobile phone?

What denotes learned and shared beliefs and behaviors?

Identified the odd one from the list below.

Who invented the bifocal glasses?

When is International day for Preservation of Ozone layer observed?

Which queen of Ahmednagar opposed emperor Akbar?

The height of a light house is 20 mts above sea level. The angle of depression (from the top of the lighthouse) of a ship in the sea is 30 deg. What is the distance of the ship from the foot of the light house?