Read the following passage and choose the correct answer to each of the questions

Ancient people made clay pottery because they needed it for their survival. They used the pots they made for cooking, storing food, and carrying things from place to place. Pottery was so important to early cultures that scientists now study it to learn more about ancient civilizations. The more advanced the pottery in terms of decoration, materials, glazes and manufacture, the more advanced the culture itself. The artisan who makes pottery in North America today utilizes his or her skill and imagination to create items that are beautiful as well as functional, transforming something ordinary into something special and unique. The potter uses one of the Earth’s most basic materials, clay. Clay can be found almost everywhere. Good pottery clay must be free from all small stones and other hard materials that would make the potting process difficult. Most North American artisan-potters now purchase commercially processed clay, but some find the clay they need right in the earth, close to where they work. The most important tools potters use are their own hand; however, they also use wire loop tools, wooden modeling tools, plain wire, and sponges. Plain wire is used to cut away the finished pot from its base on the potter’s wheel. After a finished pot is dried of all its moisture in the open air, it is placed in a kiln and fired. The first firing hardens the pottery, and it is then ready to be glazed and fired again. For areas where they do not want any glaze, such as the bottom of the pot, artisans paint on melted wax that will later burn off in the kiln. They then pour on the liquid glaze and let it run over the clay surface, making any kind of decorative pattern that they want. 

 

What does the passage mainly discuss?