Cob has been used since the 17th century as a building material. It is made by mixing dry sand, sifted clay and water. A cob house is a house that is made from this material. A benefit of using this material, is that it is sustainable and only uses natural products.
Answer:
on ,by, in ,an,of,on, at,at,of
An artifact, document, diary, manuscript, autobiography, recording, or any other source of information that was created at the time under study. It serves as an original source of information about the topic.
