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.
A pocket of continental Europe in Eastern Canada, Quebec City charms its visitors with an atmosphere all its own. This walled cityâone of the oldest in North Americaâis the capital of its namesake province and a bastion of French Canadian culture. In 1985, its Old Town was dubbed a UNESCO World Heritage Site.