The purest form of natural water is:

1. sea water
2. river water
3. rain water
4. lake water

When the water vapour changes into tiny droplets of water near the ground, it is called:

1. mist
2. dew
3. fog
4. frost

Which of the following is a source of underground water?

1. Rivers
2. Lakes
3. Ponds
4. Springs

Under normal conditions, water exists as a:

1. solid
2. liquid
3. gas
4. all of the above