Sound can travel through water for enormous distances, prevented from dissipating its acoustic energy as a result of boundaries in the ocean created by water layers of different temperatures and densities.

• Aprevented from dissipating its acoustic energy as a result of  
• Bprevented from having its acoustic energy dissipated by  
• Cits acoustic energy prevented from dissipating by  
• Dits acoustic energy prevented from being dissipated as a result of  
• Epreventing its acoustic energy from dissipating by