Sentence:  Others are confined to vast reservations , and not only does the Australian government justifiably not wish them to be viewed as exhibits in a zoo , but on their reservations they are extremely fugitive , shunning camps , coming together only for corroborees at which their strange culture comes to its highest pitch - which <WSD>is</WSD> very low indeed . 
Meaning of the word marked with <WSD> tags:  have the quality of being; (copula, used with an adjective or a predicate noun)