🔍 Key Concepts

• Difference between humidity and density of a substance • Common meteorological instruments used on ships (pressure vs moisture) • Root meanings of words like hygro- and hydro-

💭 Think About

• Which choice is specifically associated with measuring moisture in the air, not pressure or light? • Look at the prefixes: what does hygro- usually relate to, and what does hydro- usually relate to? • Which instrument would a navigator consult when interested in weather and comfort levels, like how damp the air feels?

✅ Before You Answer

• Identify which option measures air pressure or its changes over time and rule that out for humidity. • Identify which option deals mainly with liquids rather than air and rule that out for humidity. • Match the instrument whose name prefix is commonly linked to moisture in the atmosphere.