When did barack obama became a president

The two candidates engaged in three presidential debates in September and October 2008. On November 4, Obama won the presidency with 365 electoral votes to 173 received by McCain. Obama won 52.9% of the popular vote to McCain's 45.7%. He became the first African American to be elected president.

false because ozone (o3) depletion does not cause global warming, but both of these environmental problems have a common cause: human activities that release pollutants into the atmosphere altering it.

global warming is caused primarily by putting too much carbon dioxide into the atmosphere when coal, oil, and natural gas are burned to generate electricity or to run our cars.

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