Hilda shouts hey in an empty hall at the shopping mall. The sound bounces off the walls and she hears hey over and over again. Hilda has just made

PHYSICAL SCIENCES

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Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]

Hilda shouts “hey” in an empty hall at the shopping mall. The sound bounces off the walls and she hears “hey” over and over again. Hilda has just made

A	a recording
B	an echo
C	a circuit
D	a wavelength

Explanation:

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