Their economy was supported by agriculture. most were artisans, merchants, or craftspersons.
As far as I remember, the answer is: One historical contribution of the Neolithic period is the overall ability to grow crops. Neolithic period is the period when people earned advanced skills in growing corps.
Answer:
The Germans used mustard gas for the first time during war in 1917. They outfitted artillery shells and grenades with mustard gas that they fired in the vicinity of the troop target.
