explain how the ability to describe the pattern of the ice age over the past million years helps us assess a normal variation in Earth's atmosphere

What are chlorofluorocarbons made of

Which is an advantage of having memory cells when a pathogen is encountered for a second time. a) the memory cells are what proliferate into clones of cells in response to the binding of an antigen. b) memory cells are vital to the primary immune response in that they immediately recognize pathogens even at the first encounter. c) memory cells are essentially effector cells that are short lived and attack antigens even without having a receptor specific to that antigen. d) it ensures that more lymphocytes with a receptor specific to a particular antigen will be present than in a host that had never encountered that pathogen.

Mineral rich water heated by newly found oceanic crust escapes through cracks in the ocean floor called