Woon Kiat's answer to Ur mom's Primary 6 Maths Fractions Singapore question.

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Woon Kiat
Woon Kiat's answer
325 answers (Tutor Details)
1st
Hi, I am not 100% sure. But by tapping the empty can, it will generate vibrations in the air. The moving air cause the plastic cover to vibrate when the moving air touches it.