[填空题]
(a) What resonant frequency woulub e 02t hfof0f;kug7,d you e ,-vlugsh35w 1dtn+us xpect from blowing across the top of an empty soda bottle that is 18 cm deep, if yo,+hl g5t -3 vdunssu1wu assumed it was a closed tube? Hz (b) How would that change if it was one-third full of soda? Hz
