Answer:
Because you body is introduced to the virus, it is familiar to it and can build up an immunity to the weakened form so when the actual virus invades, your body know what to do.
Explanation:
Answer:
False
Explanation:
Almost all coal that is used today has its origins in the Carboniferous period. The Carboniferous period was a warm and wet one, with the majority of the land being swampy and covered with dense rainforests of ancient tree species. By the end of this period, the climate quickly changed, resulting int he collapse of the rainforests. As the trees were dying out, they were falling in the swamps, quickly being covered by the mud, so remaining largely preserved. Over time they got exposed to higher pressure and temperatures as they were getting deeper into the crust, eventually resulting in the formation of the coal.
