What is the world's largest sea body after the five oceans

The worlds largest sea is the Philippine Sea, 

The zhou dynasty (1046-256 bce) was the longest-lasting of china's dynasties. it followed the shang dynasty (c. 1600-1046 bce) and it finished when the army of the state of qin captured the city of chengzhou in 256 bce.

No, because you are more likely to see volcanic mountains where magma is rising along the mid-ocean ridge spreading to the center.