With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: Allen Iverson was in a sports league.
text_B: Carl W. Sharsmith -LRB- March 14 , 1903 -- October 14 , 1994 -RRB- was an American naturalist and Yosemite park ranger , notable for his knowledge and interpretation of the natural history of the Sierra Nevada .. natural history of the Sierra Nevada. Ecology of the Sierra Nevada. He taught botany at various universities , and was the first botanist to comprehensively document the alpine flora of the high Sierra Nevada .. TOC
not_related.