00:00

Question 108·Hard·Text Structure and Purpose

Since the early 2010s, reports of cavity-nesting bees incorporating fragments of plastic bags into brood cells have been cited as a proxy for habitat degradation: in the absence of suitable leaves, the argument goes, bees resort to synthetics. But controlled provisioning experiments in urban gardens and rural hedgerows reveal a different picture: several species incorporated plastic even when fresh leaves were plentiful, and those cells showed markedly lower rates of fungal growth. Still, the pattern is not uniformly beneficial. In sites with high ambient microplastic dust, larvae in plastic-lined cells suffered elevated mortality, likely from ingestion. The heterogeneous outcomes suggest that plastic use, while not a simple distress signal, is a context-dependent behavior ill-suited to serve as a one-dimensional index of habitat quality.

Which choice best describes the overall structure of the text?