Carbon dioxide is an example of a Greenhouse gas transported by the cardiovascular system to excretory organs and tissues
8 electrons if it is a neutral atom.
Black death, also known as the bubonic plague was one of the worst pandemics that ever happened, killing around 1/3 of Europe's population. It spread to Europe in the mid 1300's from China.
Black death victims were treated through magic, witchcraft, prayer and other methods. As for the two other options, they used medicine, but not antibiotics and radiation hadn't been discovered yet (it was discovered in the 1900's)
The pelagic zone can be contrasted with the benthic and demersal zones at the bottom of the sea. The benthic zone is the ecological region at the very bottom of the sea. It includes the sediment surface and some subsurface layers. Marine organisms living in this zone, such as clams and crabs, are called benthos.
