Volcanic rock has often been found early in the rock record but less frequently in later rock layers. What does this suggest to scientists about early earth?.

The model of human settlement suggests that uthe model of human settlement suggests that urban growth is patterned around transportation networks such as railroads and highways. a. burgess b. hoyt c. sauer d. von thunenrban growth is patterned around transportation networks

Which statement best explains the difference between weather and climate

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)