the answer is d i hope this helpss!!!
Answer:
The transcontinental railroad was built in the 1800s to connect Council Bluffs, Iowa, with the San Francisco Bay and revolutionize transport in the U.S.
Explanation:
Mongol<span> expansion into Central Asia began in 1209, as the </span>Mongols<span> pursued tribal leaders who opposed Chinggis Khan's </span>rise to power<span> in Mongolia and thus constituted a threat to his authority there. With their victories, the </span>Mongols gained<span>new territory. ... Indeed, the </span>Mongols<span> cultivated this idea.
</span>
