Questions

Coal is chemically complex fuel. Whenever it is burned, gases are given off and particles of ash, called "fly ash," are released. Release of sulfur from burning into the air. The sulfur in coal combines with oxygen to form sulfur dioxide, which can be a major source of air pollution if emitted in large enough quantities. This stuff comes back as acid rain when it attaches itself to a raindrop. 

Today, many of the effects of coal burning have been reduced significantly or eliminated. This is super-nasty and is only stopped by buying low-sulfur coal from Montana or Wyoming. The eastern power plants have to pay to move the coal from out west and this increases the price of power production.

A living community and its environment is what an ecosystem is.

The simplest organic compounds contain only the elements carbon and hydrogen, and are called hydrocarbons.

Here all the given options are hydrocarbons.

Cytoplasm does not contains all the organelles.

It is the protocol the routers in neighboring autonomous systems use to identify the set of networks that can be reached within or via each autonomous system.

The antagonist is the negative or opposing force in a story.

It could be a human enemy, or it could be non-human, like an animal or something less tangible, like fear.

The antagonist plays an important role in story development.