The Earth is roughly a sphere. The Earth is an irregularly shaped ellipsoid.
They are called fringing reefs. They grow directly from shore and form borders along the shoreline.
When a fringing reef continues to grow upward from a volcanic island that has sunk entirely below the sea level, an atoll is formed. Atolls are usually circular or oval in shape, with an open lagoon in the center.
The fringing reef is the most common type of coral reef. They however tend to be very sensitive to human induced pollution in the water and are easily destroyed by such.
Explanation:
The "doldrums" is a descriptive adjective for the corridor from around Earth closer to the equator when ships can become stuck in windless seas. In the horse elevations, where even the air moves down to towards the Earth's surface, the increasing jet stream eventually subsides.
Actually, the answer is A. I just took this test and got it right.