With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: September 11 is the date that David Angell and his wife died.
text_B: The Phetchabun mountains -LRB- ทวเขาเพชรบรณ , Thio Khao Phetchabun , -LSB- tʰiw kʰaw pʰet.tɕʰa.buːn -RSB- -RRB- are a mountain massif in Phetchabun , Phitsanulok , Loei and Chaiyaphum Provinces , Thailand .. mountain massif. mountain massif. Phetchabun. Phetchabun Province. Phitsanulok. Phitsanulok Province. Loei. Loei Province. Thailand. Thailand. It consists of two parallel mountain chains , with the valley of the Pa Sak River in the middle .. Pa Sak River. Pa Sak River. The strange rock formations of Phu Hin Rong Kla and fields where the Siam tulip flower -LRB- Curcuma alismatifolia -RRB- , known as dok krachiao in Thai , grows wild are some of the characteristics of the Phetchabun Mountains .. Phetchabun. Phetchabun Province. Siam tulip. Curcuma alismatifolia. Thai. Thai language
not_related.