How did the domino theory influence the united states' role in the vietnam war?

The need for new trade routes to the east, the desire to spread christianity, and competition between european countries all contributed to the:

Question 1(multiple choice worth 5 points) the yalta conference failed to achieve which outcome? germany would be divided into zones of occupation. stalin would support the effort to create the united nations. stalin would join the war against japan after germany's defeat. german zones of occupation would have free elections.

How did the incas unite the andes mountains?