2. What does letter B represent on the Earthquake model? A:Epicenter
B:Focus
C:P wave
D:O S wave

A.

Explanation:

The letter B represents the Epicenter of the earthquake.

The focus would be the letter A and C would be called the fault.

The epicenter is the point closest to the point where the earthquake originated but on the surface and not underground. The hypocenter is the point within the earth where an earthquake rupture starts.

sulfur dioxide

explanation: acid rain is caused by a chemical reaction that begins when compounds like sulfur dioxide and nitrogen oxides are released into the air. these substances can rise very high into the atmosphere, where they mix and react with water, oxygen, and other chemicals to form more acidic pollutants, known as acid rain.

the oldest known insects are believed to live around 400 millions ago as suggested by the fossil records.   some plants having woody stems also evolved during this time.

after the evolution of insects the first four legged species or the tetrapods evolved in shallow freshwater habitats from the intermediate species approximately 397 million years ago. the tetrapods went on conquering the land giving rise to amphibians, reptiles, mammals and birds.

the major split in tetrapods first occurred 340 million years ago branching off from amphibians.

363 million years ago when the carboniferous period began the insects started roaming on land and taking flights, following which the four limbed tetrapods adapted in the terrestrial habitat.