Question: 

A coral reef is a flower garden of stone, growing like a wall or like a tower from the depth and filled with the most confusing and most colorful varieties of life.The colors are beautiful, especially in the shallow region down to sixty feet,where some of the red and yellow light of the sun's rays still penetrates. But most corals are greenish, brown, bluish or yellow.Coral reefs often shelter and food to thousand of creatures.The warmer the climate, the grater the variety of species there is.In the tropics, it is easier to find, in one place, ten different species than ten specimens of the same species and a coral reef provides ample proof of that rule.Living conditions are most favorable, so that many forms are able to develop and survive in their struggle for existence.

The main subject of the passage is-

The beauty of a coral reef
The correlation of climate and life
The struggle for existence
The colors of a coral reef
Answer: 
The struggle for existence
Last Updated: 
18/09/2020 - 01:18