At the earth's surface, warm air expands and rises, leaving behind what is known as an area of ; cold air is dense and sinks to the surface to create what is known as an area of

low pressure ; high pressure

Explanation:

Hi, At the Earth's surface, warm air expands and rises, leaving behind what is known as an area of low pressure; cold air is dense and sinks to the surface to create what is known as an area of high pressure.

High pressure is associated with sinking air, and low pressure is associated with rising air.

This is due to the airflow. Airflow is directed slightly inward toward the low-pressure center, this causes the air to converge until it faces with the surface and is forced upward ( causing condensation and precipitation).

On the other hand, Airflow is directed slightly outward away from the high-pressure center at the surface, so as a result, air from above must sink to take its place.

convex lenses are thicker at the middle. rays of light that pass through the lens are brought closer together (they converge). a convex lens is a converging lens. when parallel rays of light pass through a convex lens the refracted rays converge at one point called the principal focus.

33: i think it’s b