Other viruses that can cause colds include coronavirus, respiratory syncytial virus, influenza and parainfluenza. Colds cause a lot of people to stay home. The CDC says 22 million school days are lost each year in the U.S. because of them. Some estimates say that Americans have 1 billion colds a year. For more detail, see Common Cold Causes. How a Common Cold Starts. You can catch it from another person who is infected with the virus. This can happen by direct physical contact with someone who has a cold, or by touching a surface contaminated with their germs -- like a computer keyboard, doorknob or spoon --- and then touching your nose or mouth.
The hypocaust system. The hypocaust system (hypocaustum in Latin) was a heating system used in (wealthy) Roman homes and Roman baths, and the closest thing to central heating today. The hypocaust was a system that circulated hot air under the floor and surrounding walls. Hypocaust construction
The above weapons are the main weapons of the Roman heavy infantry man, however, the Romans employed a number of other weapons as well. For example the pugio was a dagger used as a sidearm by the roman legionnaires. It featured a wide leaf shaped blade and was about 9.5 - 11 long.During the first and second centuries AD, the spathea became a common weapon of choice.he gladius served the Romans as the main Roman weapon through the rest of the Roman Republic and partially through the Empire (4th century BC - 3rd century AD). The Legions that poured from Rome to conquer the Mediterranean world held this weapon in their hand.