With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: Lung cancer results in deaths.
text_B: Amy Burvall is an American educator known for her innovative teaching videos produced jointly with her colleague Herb Mahelona which describe historical events in song to the soundtrack of pop music hits .. Herb Mahelona. Herb Mahelona. The videos were originally produced just for school use but have been viewed over one million times since they began to be published on YouTube .
not_related.