Which example describes a method of relative dating?

a. measuring the depth of tree bark

b. examining historical records to determine when a volcano erupted

c. using fossils to determine the oldest rock layer in a canyon

d. using radioactive isotopes to calculate the age of a rock

Which of the following accurately describes the workforces of the united states and canada? a. most of the workforce in the united states and canada is employed in the service industry. b. most of the workforce in the united states and canada is employed in the educational field. c. most of the workforce in the united states and canada is employed in manufacturing and mining. d. most of the workforce in the united states and canada is employed in agriculture.