On land they used camels to carry goods and caravans to actually travel in.
When they were near water they used ships.
The Vice President takes his or her place until the President is well enough or until there is a need for another president.
The development of agriculture was a hallmark for the development of human civilization. Before that, humans had to focus their efforts on hunting and harvesting for food, so the effort existed to sustain life. After the development of agriculture, civilizations came to have a food security, that is, subsistence is no longer a doubt. From then on, society can turn its attention to other activities and has experienced a major evolution. One of the activities by which people could develop was work, which eventually led to the development of technologies. The industrial revolution is the result of the human capacity to work and create technological tools. This was only possible after the population had a food security, thanks to the agriculture revolution.
When a hole in the ground is formed by chemical waste.
The answer is a. the emphasis on peaceful resolution