Answer:
Sound Navigation Ranging - SONAR
Zoning Improvement Plan - ZIP
Radio Detecting and Ranging - RADAR
National Aeronautics and Space Administration - NASA
Housing and Urban Development - HUD
Self-Contained Underwater Breathing Apparatus - SCUBA
Explanation:
Since acronyms are just abbreviations of words, let's take a look at those words.
Self-Contained Underwater Breathing Apparatus
Sound Navigation Ranging
Radio Detecting and Ranging
National Aeronautics and Space Administration
Housing and Urban Development
Zoning Improvement Plan
We're going to take these and bold the parts that would probably make up an acronym- usually the first letters.
1. Self-Contained Underwater Breathing Apparatus - SCUBA
2. Sound Navigation Ranging - SONAR
6. Radio Detecting and Ranging - RADAR
4. National Aeronautics and Space Administration - NASA
5. Housing and Urban Development - HUD
6. Zoning Improvement Plan - ZIP