The two main gases making up the lower atmosphere are

The lines marked by the letters a, b, and c on the map above represent a. chains of volcanoes b. earthquake fault lines c. thin strips of heavy forests d. major rivers that flow from north to south

This word for a bug or malfunction was popularized in the 1962 book into orbit by the mercury astronauts

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)