Answer:
the battle of yorktown
Explanation:
General Lord Cornwallis surrendering his sword and his army to General George Washington and the Continental and French armies after the final battle of the Revolutionary War on October 19, 1781 in Yorktown, Virginia
Oleg defeated the Khazars, delivering several Slavic tribes from dependence upon them, and also undertook a successful expedition against Constantinople (907), forcing the Byzantine government to sue for peace and pay a large indemnity.
It affected them immeasurably because it enabled them to trade this surplus of food for things that they might need from other countries and thus get other pieces of technology or knowledge or anything similar. They could improve their state that way and that's how development of civilizations began.
Answer:
built dams to provide for irrigation
converted bad land into agricultural fields
invented new farming methods
