1) Sound is the kind of  a) work b) energy c) force d) none 2) vibration is a) visible b) invisible  c) can both (a) and (b)  d) non 3) sound can not be produce without vibrations a) true b) false

class 9th

de
Imprimir
Incorporar

Ranking

Estilo visual

Opções

Alterar modelo

Restaurar arquivo salvo automaticamente: ?