Questions

The light from the sun takes about 8 minutes to reach the Earth after it has been emitted from the sun's surface.

The time it takes for light to reach planets in our Solar System varies from about 3 minutes for Mercury to about 5.3 hours for Pluto.

1. Lichens are plants that grow in exposed places such as rocks or tree bark.

2.  Lichens are widely used as environmental indicators or bio-indicators. They can be used as air pollution indicators, especially of the concentration of sulfur-di-oxide in the atmosphere.  

3. They need to be very good at absorbing water and nutrients to grow there.

Later in 1840, Rowland Hill invented the stamp, which was paid for by the sender, not the receiver.

Strait is nothing but a narrow passage of water which connects two seas or other large areas of water. Here Palk strait is the strait that separates India from Sri Lanka.