NSO Answer Key 2019-20: NSO Answer Key 2019-20 is available online for SET A and B, by coaching institutes. Candidates can easily download the answer keys of NSO 2019 from the official website,www.sofworld.org/nso, for class 1 to class 11 available since November 12, 2019. Science Olympiad Foundation (SOF) will publish the official NSO answer key 2019 for Set A and Set B at … [Read more...] about 22nd NSO Answer Key 2019-20 | Download NSO Answer Key Set A from Here