The notches on both sides of ax are shown the
shape of spike of wheat. There are two sets on each side, one set point to upper direction, the other set facing downward. In addition, the Xia Dynasty turquoise flog plate and the Xia Dynasty jade ring with frog low relief motif further explain that Xia Dynasty has rice field which is a sign of agricultural settings. The important event happened in the Xia Dynasty may the great flood in about 2000 BCE according to the research reported in BBC news.