When soil lacks nutrients needed for crop growth, farmers might add to the topsoil to promote the growth of crops.

Ships can transit between the atlantic and pacific oceans using the canal.

Agricultural practices in the united states nearly led to the extinction of the peregrine falcon during the 1950s and 60s.

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)