When coal has reached it hardest, darkest form, it is called select one: 0 a. sub-bituminous b. lignite c. bituminous d. antrhacite next page

When the coal reaches its hardest and the darkest form then it is termed as anthracite.

Option D

Explanation:

The hardest among the coal is called as the anthracite. It has large amount of carbon atoms and it is also regarded as the best quality of coal that is being mined.

This is mostly prevalent in South Korea, North Korea, United states, United Nations, Canada etc. This is mainly used in the steel making process and is combined with many alloys for enhancing their property.

homeostasis is the tendency towards a relatively stable equilibrium between interdependent elements, especially as maintained by physiological processes. and this is how it applies to the integumentary system. back to top. skin functions in homeostasis include protection, regulation of body temperature, sensory reception, water balance, synthesis of vitamins and hormones, and absorption of materials. when body temperature falls, the sweat glands constrict and sweat production decreases.

not always but somethings can be reproduced in a laboratory.