What conclusion would you draw if a seismogram from a particular seismic station showed only P waves? Why is it better to use data from three or more seismic stations to find the epicenter of an earthquake? How does the time between the arrival of S and P waves relate to the distance of the station to the epicenter?

Scientists think that convection currents flow in earth’s a. continents. b. mantle. c. lithosphere. d. inner core.

How can minerals crystallize from materials dissolved in water? check all that apply.

Which barrier to economic development is shown in the following examples? i. the high rate of hiv infection in underdeveloped nations ii. the use of children as soldiers in uganda’s army in the early 2000s iii. low literacy rates in underdeveloped nations with limited exposure to adequate education a. foreign debt b. political instability c. widespread disease d. low levels of social welfare