9. Which of the following statements is TRUE?

A. Sound needs a medium to travel.
B. Sound can travel in outer space.
C. Sound travels faster in liquids than in solids.
D. Sound is louder when you are far from where the sound is coming from.


10. Light and sound waves can be reflected, refracted, and transmitted. Which of the following is an example of reflection of light and sound?

A. image formation in mirrors and production of echo
B. image formation in both light and sound waves
C. image formation in mirror and production of music
D. production of echo in both light and sound waves​