Answer: B
Explanation: echos cannot be made from light waves so C and D are out, and sound waves cannot travel into a surface. Also echos is sound waves bouncing that’s why in an empty room without furniture there’s an echo.
Answer:
It is none. Echo is formed when sound waves hit a hard surface.
Explanation:
Answer: 334000 Liters
- $Supreme$
Sodium,aluminium,sulfur and chlorie
6.104x10^2=610.4
9.5x10^3=9500
