2. Humans discovered how to use fire and tools. How was this knowledge passed along to younger generations? O Younger people were forced to spend long hours building fires and making tools. O Communication skills were developed so knowledge could be passed along to younger generations. The younger generations were able to figure out how to use tools on their own. O Primitive knowledge was instinctive so that the basic skills of fire and tools came naturally to everyone.

This is a type pf behavior that animals are born with and them to survive

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.

Which of these is most likely to happen if parallax measurements of star distances are taken after a gap of six months? the results would be accurate the results would be inconsistent the results would not be valid the results would not be repeated