The Arabs used to kill their daughters by throwing them into a well etc.However,before being a prophet Muhammad(sav) used to carry his daughter on his shoulders.After Islam,Kur'an banned killing of these children.These are 2 simple examples.
The dictionary definition is:the practice of treating individuals differently because of their race or color
The answer is: It allowed the farming society to dig up the dirt on their farms allowing a more effective and easy way to plant their crops.
The method of farming contributed by the invention of plow allow societies to produce more products with lesser amount of time (most popular one would be by combining it with animals such as buffalo or horses) . This invention help to address hunger problems that exist at that time and bring wealth and prosperity through the agricultural sectors.
When she was 12, she loved challenging the neighborhood boys in running and jumping.