Put the following paragraph into Chinese.
The reason for not classifying carbon dioxide as a
pollutant is that it is a natural component of the atmosphere and needed by
plants to carry out biological synthesis. No one would argue that carbon dioxide
is a necessary component of the atmosphere any more than one would argue the
fact that Vitamin D is necessary in the human diet. However, excess intake of
Vitamin D can be extremely toxic. Living systems, be they an ecosystem or an
organism, require that a delicate balance be maintained between certain
compounds in order for the system to function normally. When the excess presence
of one substance threatens the wellbeing of an ecosystem, it becomes toxic
despite the fact that it is required in small quantities.