Final answer:
Air sinks and high-pressure systems are found at the Earth's surface.
Step-by-step explanation:
At the Earth's surface, air sinks in high-pressure systems. High-pressure systems are characterized by sinking air, which creates a region of high atmospheric pressure. In these regions, air is descending and compressing, causing it to warm and inhibit the formation of clouds and precipitation. Examples of high-pressure systems include anticyclones and subtropical highs.