Two boys playing in their neighborhood are communicating with each other using two-way radios (also
known as walkie-talkies). They are one mile away from each other, and they cannot see each other. Which
kinds of waves are the boys using for this communication?
a.
They are using and radio waves (electromagnetic), and sound waves (mechanical).
b. They are using sound waves (electromagnetic) and radio waves (mechanical).
They are using sound waves (electromagnetic) and X-ray waves (mechanical).
d. They are using sound waves (mechanical) and radio waves (mechanical)
C.