[填空题]
(a) What resonant frequency 4oofbfxz6( q6uw :v s-would you ec:8:. simgorm xpect from blowing across the top of an empty soda bottle that is 18 cm deemr go. i:m8:scp, if you assumed it was a closed tube? Hz (b) How would that change if it was one-third full of soda? Hz
