It was crucial due to the fact the Egyptians was dependent on the cycle of the Nile River. The Egyptians recognized three seasons: Akhet (flooding), Peret (planting), and Shemu (harvesting). The flooding season lasted from June to September, depositing on the river's banks a layer of mineral-rich silt ideal for growing crops. After the floodwaters had receded, the growing season lasted from October to February. Farmers plowed and planted seeds in the fields, which were irrigated with ditches and canals. Egypt received little rainfall, so farmers relied on the Nile to water their crops. From March to May, farmers used sickles to harvest their crops, which were then threshed with a flail to separate the straw from the grain. Winnowing removed the chaff from the grain, and the grain was then ground into flour, brewed to make beer, or stored for later use.
Answer: His arms muscles work in pairs so that one contracts while the other relaxes as he climbs up.
Explanation: when we exercise one muscle, there is usually another muscle that isn't the target of the exercise but it helps us maintain the form by doing the opposite movement. For example, when we do a bicep curl, the muscle that we are working is the biceps, and it contracts, but at the same time, the triceps relaxes, this is called antagonist muscles. The same thing happens when a rock climber climbs up the rock wall, the biceps contract as he pulls up and the triceps relax at the same time.