Answer:
A duty is what you owe to your fellow human as a fact of nature, and an obligation is what has been imposed by contract or custom. Generally, one is “obliged,” or “obligated,” by agreement or because of having received a benefit. If you take candy from a store, you have an obligation to pay for it.
China's first imperial dynasty was the Qin dynasty. The Qin unified the Chinese Warring States by conquest, however their empire ended up becoming unstable, after the death of the first emperor Qin Shi Huang.
Answer:
I think it's chemicals sold to pharmaceutical developers... i don't know if it's right, though... i'm only in 8th grade, so it could be wrong, so wait until you get some more answers, and then double check each one. Hope it helps!