Directions: Read the passage and answer the following questions. Sound is caused by vibrations. Air is a gas water is a liquid. Gases are very thin in comparison to liquids, so when a sound travels through air it vibrates the air very easily without much distortion (changes). When a sound travels through a liquid it has to move through a thicker substance. This means that the sound has more difficulty causing the vibrations. So although sound travels better in water, it is harder to hear properly. Sound is caused by:

• A. Dancing        
• B.          vibration      
• C. Jumping          
• D.          none of these