All of the following regions in the united states have the highest population density, except the
a. southwest
b. northeast
c. pacific coast
d. great lakes

Which of the following is not an effect of land substance

Geologists know that potassium-40 decays to argon-40, with a half-life of 1.3 billion years. if an analysis of a feldspar crystal in a sample of granite shows that 75 percent of the potassium-40 atoms have decayed to form argon-40, what is the age of the granite

Which factors add to the greenhouse effect and are caused by human activities?