🤔 According to the text, what is the primary sense that fog signals appeal to?
Difficulty: Easy
🧐 According to the text, what were once considered serious obstructions to sound, but have since been scientifically proven to have no sensible power to obstruct sound?
Difficulty: Medium
🤯 What does the text suggest is the true test of a sound signal's effectiveness, rather than how far it can be heard under ideal conditions?
Difficulty: Hard
Sign Up To Try Advanced Features
Get more accurate answers with Super Search, upload files, personalized discovery feed, save searches and contribute to the PandiPedia.