How many of the world’s 20 largest cities are located in western europe?
a.
none
b.
one
c.
two
d.
four

The first atomic explosion was detonated in the desert north of alamogordo, new mexico, on july 16, 1945. what percentage of the strontium-90 ( yr) originally produced by that explosion still remains as of july 16, 2016?

Which type of map gives the most information about what lies below the surface terrain ?

Which of the following is the unit of measurement used to describe the severity of an earth quake?