When getting a vaccination, which substance is
injected into the body?
(1) bacteria to combat a pathogen
(2) white blood cells to engulf a pathogen
(3) a weakened form of a virus
(4) antibiotics to kill a virus

succession returns a disturbed

ecosystem to a more stable state. this is also classified into two (2) types:

primary succession and secondary succession. the primary succession arises when

a new land is transformed and a bare rock has been exposed providing an environment

that can be occupied for the first time. while, secondary succession occurs

when a previously occupied environment was disturbed that kills much of all its

community

explanation: