Why is the weather likely to be clear and sunny when the air pressure is high, and wet and rainy when the air pressure is low?

High-pressure systems are frequently associated with light winds at the surface and subsidence through the lower portion of the troposphere. In general, subsidence will dry out an air mass by adiabatic or compressional heating. Thus, high pressure typically brings clear skies.

Explanation:

answer : haversian

[explanation: -(compact bone is organized as parallel columns, known as haversian systems, which run lengthwise down the axis of long bones. these columns are composed of lamellae, concentric rings of bone, surrounding a central channel, or haversian canal, that contains the nerves, blood vessels, and lymphatic system of the bone)]