Every year May 28 is celebrated as the _______________.

In _________, the United Nations General Assembly proclaimed September 16 as the International Day for the Preservation of the Ozone Layer.

Which country was the first to celebrate world tourism day?

Which day promotes preventative measures to reduce the risk of cardiovascular diseases.

Though frogs have a pair of lungs they can also breathe through their ______________.

During inhalation, our lungs ____________.

Heat from the sun reaches us by the process of _________.

A black body with a rough surface is a_____________.

Normal temperature of human body is ___________.

When is World Heart Day celebrated?

Lactic acid is found in _______________.

20% of Earth's oxygen is produced by the ______________rainforest.

Which of the following begin their life as tadpoles?

Dolphins are _______________-