How does the playwright use dialogue to develop the message in this passage?

whether dad arrives in time for the game depends on his conference. subject

one of the central themes of edward abbey's work has been his staunch opposition to the glen canyon dam on the colorado river that created lake powell, destroying stunning scenery and wildlife habitat, endangering many rare species of fish and animals, and also irreparably destroying many important archaeological sites which provided information about the early inhabitants of the united states.

sigh language, body language, and voice telepathy