What is the main cause of urban migration in the United States? a. Rural communities are no longer necessary.
b. Urban dwelling provides better access to goods, services, and jobs.
c. Urban communities reduce human impact on the environment.
d. Rural communities are unable to support life in the long-term. .

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.