This graph best represents the populations of marine groups before and after the
a. cambrian explosion
b. ordovician extinction
c. permo-triassic extinction event
d. alleghenian orogeny

Which of the following regions has what is considered the most rugged terrain in oklahoma? a. the wichita mountains b. the arbuckle mountains c. the sandstone hills d. the ouachita mountains

In the developed world, women are increasingly more likely to delay childbirth until their mid- to late- twenties or long because

In which area will soil formation be greatest? a a steep slope in a warm,b wet climate a flat area in a warm,c wet climate a north-facing area on a steep slope a flat area in a cold, d wet climate description