With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: Michael McCary was in the R&B group Boyz II Men as a singer.
text_B: An escape set -LRB- in German Tauchretter = `` diver rescuer '' -RRB- is a breathing set , which lets its wearer survive for a time in an environment without -LRB- sufficiently -RRB- breathable air , in particular underwater , primarily or originally intending mainly to survive long enough to reach safety where the air is breathable .. breathing set. Self-contained breathing apparatus. Early escape sets were rebreathers and were used to escape from a submarine which was submerged so long that its onboard air supply ran out , and for technical or military reasons the submarine could not surface  : one example is the Davis Submerged Escape Apparatus .. Davis Submerged Escape Apparatus. Davis Submerged Escape Apparatus. Escape sets were also used ashore , e.g. in the mining industry .. mining. mining
not_related.