The first paragraph of the text deals mainly with the earth atmosphere's.

A．the circulation of atmosphere protects the biosphere and makes life on earth possible.
B．if the protective atmosphere is too damaged by human activity, all life will cease.
C．life is the result of complex interdependent events of nature
D．despite the complexity and power of the atmosphere humans can affect it greatly

A．are not able to analyze and judge advertisements
B．often give off information that may be dangerous to them
C．are unable to give consent since they are too young
D．are not ready to evaluate advertisements in terms of accuracy