Which is one factor that scientists use to classify orders of soil

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)

Which measure of humidity, relative humidity or dew point, best describes the actual quantity of water vapor in a mass of air

Which of teh following would explain the importance of the trans-siberian railroad to russia's economy? (schoology test)