🔍 Key Concepts

• Air mass: a large body of air with fairly uniform temperature and moisture. • Front: the zone or boundary where two different air masses meet. • Isobar: a line on a weather map connecting points of equal pressure.

💭 Think About

• Think about which option describes a line or zone of meeting between two different types of air, not the air itself. • Ask yourself which choice is normally shown on a surface weather chart as the dividing line between warm and cold air. • Consider which term is used by mariners in forecasts like "a cold _____ will pass the area tonight."

✅ Before You Answer

• Verify which term specifically means a boundary between contrasting air masses, not just any weather line or feature. • Check which option is commonly associated with warm, cold, stationary, and occluded in marine weather forecasts. • Eliminate any options that refer to geography (land features) or pressure lines, since the question is about air masses.