. Which of the following can cause different types of rocks to form?

No mercy for the user europa2433 because he or she reports everyone. and its annoying. come on who agrees.

One drawback of voluntary trade is that it a.requires two groups to use a common language b.can make one group dependent upon another for necessary goods c.doesn't occur unless there is a shortage of goods for at least one group d.forces groups to rely on themselves to produce all the goods they need

How have the united states influenced other nations? describe the impact that the u.s. has had on other countries.