Why was the mongols' sheep-based economy unstable?
a. droughts and long winters sometimes ravaged the herds.
b. inbreeding caused the herds to weaken and die out.
c. chinese raiders often stole entire herds of sheep.
d. other nations would not trade for the mongols' sheep

How did inovations in manufacturing lead to improvments in transportation?

Who believed that the best economic system was on in which businesses compete to gain profit with minimal or no government control

How are the republican and democratic presidential candidates chosen? a. they are nominated by their state governments. b. each is nominated by his or her respective party. c. each is chosen by the governor of his or her home state. d. they are chosen by the house of representatives.