With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: Thor: The Dark World did not get any reviews.
text_B: The EF 100 -- 300mm refers to three telephoto zoom lenses produced by Canon .. Canon. Canon ( company ). They are of the EF lens mount that is compatible with the EOS line of cameras .. EF lens mount. Canon EF lens mount. EOS line. Canon EOS. The three versions are  :. 5.6. 5.6 L. 4.5 -- 5.6 USM
not_related.