听一段材料，回答下面几个小题。
What did Obama's victory mean?
A. He became the 41st President of the United States.
B. He became USA's first black President-elect.
C. He will be the first African-American in the US history.
Which is NOT mentioned as a serious challenge for Obama?
A. Civil wars.
B. Climate change.
C. Financial crisis.
When did Obama exercise his duty as President?
A. On January 20, 2009.
B. On January 12, 2009.
C. On February 20, 2009.
Which of the following best describes how Obama felt in his victory speech?
A. Dependent and joyless.
B. Hopeful and confident.
C. Proud and over optimistic.