Although only about one person in ten with a positive skin test or blood assay ever develops. TB disease, the risk continues throughout the rest of your life. The symptoms of TB are. common to many other illnesses.
Marco Polo-Great Silk Road. For many centuries the Great Silk Road connected a complex network of trade routes from Europe with Asia. It was a way to establish contact with the great civilizations of China, India, the Near East and Europe.
How long did it take Marco Polo to reach China?   When Marco was 17, he accompanied his father and uncle on their second journey to Asia. The Polos had traveled 5600 miles (9000 km) in over three and a half years to rea â¦ ch Cathay.