Dust particles are natural in the environment but when they combine with vehicle emission particles they form a particulate matter
b. ultrafine particles
c. reactive chemicals
d. inactive chemicals
e. lead particles

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.

Can someone i have no idea of how to do this.

Which of the following are not included as modern mammals that evolved during the eocene epoch? primates artiodactyls perissodactyls none of the above