Questions

It is Blackboard or Chalkboard which is Black when clean, and as you write on it with white chalk it becomes dirty in White color.

In a computer, the area where the data is stored for the quick access by the computer's processor is called Main storage or Primary storage or Memory or RAM.

Hence, main storage is also called Memory.

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.

During vigorous exercise capillaries of the active muscles will be engorged with blood.

Digboi has the distinction of being India's oldest continuously producing oilfield. Digboi refinery, now a division of Indian Oil Corporation, had a capacity of about 0.65 MMTPA as of 2003. Digboi is now Headquarter of Assam Oil Division of Indian Oil Corporation Limited, though the crude production is not high today.