With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: The Gray wolf is a part of the food chain.
text_B: Mark Twain Sr. .. High is an alternative high school located in Linda Vista , San Diego , California , part of the San Diego City School District .. San Diego City School District. San Diego City School District. Category  : High schools in San Diego. Category  : Public high schools in California
not_related.