Viruses cause a number of diseases in eukaryotes. In humans, smallpox, the common cold, chickenpox, influenza, shingles, herpes, polio, rabies, Ebola, hanta fever, and AIDS are examples of viral diseases.Even some types of cancer -- though definitely not all -- have been linked to viruses.n humans, smallpox, the common cold, chickenpox, influenza, shingles, herpes, polio, rabies, Ebola, hanta fever, and AIDS are examples of viral diseases. Even some types of cancer -- though definitely not all -- have been linked to viruses.
Map of the fortifications. Located in Canada, the Ramparts of Quebec City are the only remaining fortified city walls in North America north of Mexico. The British began refortifying the existing walls, after they took Quebec City from the French in the Battle of the Plains of Abraham in 1759.
Along the curtain wall, at intervals, are thirteen square or rectangular towers. Battlements. The top of the castle walls were the battlements, a protective, tooth shaped parapet often with a wall walk behind it for the soldiers to stand on. The defenders could fire missiles through gaps (crenels).The raised sections between, called merlons, helped to shelter the defenders during an enemy attack.long the curtain wall, at intervals, are thirteen square or rectangular towers. Battlements. The top of the castle walls were the battlements, a protective, tooth shaped parapet often with a wall walk behind it for the soldiers to stand on. The defenders could fire missiles through gaps (crenels).