Only two markers of human activity are evident in the stratosphere.

They are indicated by .

Select one:
a. the condition of the ozone layer and the presence of spy planes
b. the flight of rockets and transmission of radio signals
c. the weather that we experience and commercial airplane flight

d. the presence of satellites and the International Space Station

Option A. the condition of the ozone layer and the presence of spy planes.

Explanation:

Stratosphere is very important layer because a very important gas i. e. Ozone is present. Ozone gas makes a layer around the earth which prevents the earth from harmful ultraviolet radiation of the sun. This radiation causes skin disease such as skin cancer. Aeroplane and jets also fly in this region.

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: