[填空题]
(a) What resonant frequeyvl1 ylr k1r7(n0-vwp dqqu 9vxnu 99.ncy would you expc s hk)n):5bx,i cqs04xqm-ptect from blowing across the top of an empty soda bottle that is 18 cm deep, if you assumed it sxx-s,)q0b kh5 pc)c:tn4qim was a closed tube? Hz (b) How would that change if it was one-third full of soda? Hz
