Which of the following is true? a. Extinctions of past species has happened gradually and on a small scale.
b. Bacteria represent a newer form of life, not present during the early prehistory of Earth.
c. Most organisms present early in Earth's prehistory were more complex than modern organisms.
d. Species on Earth today are but a fraction of all species that ever lived.
e. The number of species existing at one time has decreased throughout history.

D

Explanation:

So many species on the Earth have gone extinct throughout it's years. Many species have died out over the 4.543 billion years that the earth has existed, and new species are introduced throughout the decades whilst some fade out.

weathering is the answer.

the water is warmed up by the sun and then it evaporates into the atmosphere. the sunlight warms the water by its heat. water is then cooled down and condensation takes place. the water then finally returns back to the earth by the process of precipitation in the form of rain or ice.

explanation: