It is important that you do not expel the air or the barium. The air is used to expand the walls of the colon for a more detailed look at the lining of your colon. After the barium and air is in, the technologist will take a series of X-rays of your colon. You will be asked to hold your breath and remain still during the picture. An imaging physician will review the images to make sure that they are sufficient to make a diagnosis. If they are not, more pictures may be taken.
However, it is not known how the builders got the huge wooden support columns into position. Unlike western architecture, in ancient Chinese wooden architecture, the wall only defined an enclosure, and did not form a load-bearing element. Buildings in China have been supported by wooden frames for as long as seven millennia.
3. City Wall â Xian. The symbol of Xian is its amazing City Wall, which was built during 618 â 907 of Old Tang Dynasty. It is the most complete city wall that has survived in China, as well being one of the largest ancient military defensive systems of the world. The wall now stands 12 meters tall, 12-14 meters wide at the top and 15-18 meters thick at the bottom.