Read the following sentence from the section "Challenges To Sustainability".
A lot of issues need to be addressed,
like how land is used, how jobs are
created and issues related to
economic disparity.
Which phrases from the article help to explain
what "economic disparity" means?

Based on the observation that only male crickets produce a song, you hypothesize that a male's song is a form of communication to potential mates. you set up a simple experiment to test this hypothesis. in the laboratory, you place a male snowy tree cricket in enclosure a, which is adjacent to enclosureb. in enclosure b, you place other insects, one at a time, and observe their responses to the male's song. the enclosures are designed so that the two insects being tested cannot see or smell each other, but sound is transmitted from enclosure a to enclosureb.