Tiny drops can appear on a cool surface even when no rain has fallen. Nearby mois condenses in liquid drop because coo reduces t amount o water th surrounding a can ret under th particular local conditions. A cold drinking glass provides a familiar example. Water on its outside need not have passed through the glass; it can come from the air around it. The surface temperature and the amount of moisture in the air both matter. Explaining the drops therefore requires considering the glass together with its immediate surroundings.

Type only the missing letters. Each box is one letter, and the number of boxes matches the letters that are missing.