Zax, David2017-04-202017-04-2019481948b146811097824029https://hdl.handle.net/2144/21540Thesis (Ed.M.)--Boston University, 1948. This item was digitized by the Internet Archive.en-USBased on investigation of the BU Libraries' staff, this work is free of known copyright restrictionsThe present status of certain audio-visual aids in the biology classrooms of the public senior high schools in the state of MassachusettsThesis/Dissertation