Answer:The Articles of Confederation
Explanation:
In 139 B.C.E., the Chinese emperor dispatched Zhang Qian to central Asia to seek allies against the Xiongnu. The Xiongnu were a large confederation of Eurasian nomads who dominated the Asian Steppe.
The answers are, in order, the Krebs cycle and oxidative phosphorylation.
A. Developing a vaccine to prevent Polio. I just took the test :)
