What is the importance of dust, volcanic ash, & salt in the atmosphere

In 1915 the german geologist and meteorologist alfred wegener first proposed the theory of continental drift, which states that parts of the earth's crust slowly drift atop a liquid core. the fossil record supports and gives credibility to the theories of continental drift and plate tectonics.

Which of the following statements about the migration of workers to other countries is false?

Name one type of data that h-r diagrams do not show.