Select all that apply. Tragically, the United States lost astronauts in accidents involving:

Challenger
Columbia
Apollo 11
Viking 11
Vostok 1

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:

a. to encourage apoptosis