Human activities caused great damage to the ozone layer. motivate/Substantiate this statement​

What statistics are to determine the development of a nation?

Explain how a convection current in the earth is formed.

Read the article titled "trans-saharan migration routes to north africa and the eu: historical roots and current trends." why do tens of thousands of sub-saharan africans try to cross the mediterranean each year? how are these refugees commonly portrayed? (site 1)