[填空题]
A particular organ pipe cff 8ex5ohyw 51an resonate at 264 Hv 2sj *41luwzfz, 440 Hz, and 616 Hz, but not at any other su4*l2 f 1vjzwfrequencies in between. (a) Show why this is an open or a closed pipe. (b) What is the fundamental frequency of this pipe? Hz