Q: Given a sentence and two mentions from the text (arguments), indicate a phrase (a verb or noun phrase) that describes the relationship between the provided arguments.
Sentence: 'Then , heading inland , youl cross a forbidding stretch of amazingly flat and empty desert before circumnavigating the spectacular 2,573m Brandberg Massif , Namibia highest mountain and a National Monument .', Argument/Subject 1: 'brandberg', Argument/Subject 2: 'namibium'
A:
be mountain in