In the skin, the epidermis can be compared to which of the following?
a wall that protects a country from invaders
a ship that transports cargo
a telephone line used to communicate information
a switch that turns a light on

Which of the following are not matched correctly? cd8+: directly destroy infected or cancerous cells t reg cell: reduce the adaptive response once threat passes t l: activate cellular branch (cytotoxic t cells, macrophages, nk cells) t 2: stimulate b cells to make antibodies t (cd4+): mhc i