043.
Forty-eight years ago Martin Luther King had a dream of an America where men and women would be judged not on the colour of their skin but on the content of their character. Today what America has done is turning that dream into reality.
After a hard-fought campaign, Democratic Senator Barack Obama won the US presidential election, and became the 44th President of the United States--the first African-American in the country's history to do so.
President-elect Obama did not take office until January 20th, 2009. However, when he became president, he faced many serious challenges, including two foreign wars, climate change and what he described as "the worst financial crisis in a century".
But Obama himself appeared to enjoy the flavor of the challenge. In his victory speech, "The road ahead will be long. Our climb will be difficult. We may not get there in one year or even in one term, but America--I have never been more hopeful than I am tonight that we will get there," said the President of the United States.

答案解析：
(1) 正确答案为B。根据the first African-American in the country's history to do so.他是美国历史上第一位当选总统的非洲裔美国人。可推知，他是美国首位黑人总统，因此B项正确。
(2) 正确答案为A。根据he faced many serious challenges, including two foreign wars, climate change and what he described as "the worst financial crisis in a century".他面临着许多严峻的挑战，包括两个国外战争，气候变化，以及他称为“一个世纪以来最严重的金融危机”。可知，奥巴马面临的挑战包括气候变化和金融危机，而内战则不包括在内，因此A项正确。
(3) 正确答案为A。根据President-elect Obama did not take office until January 20th, 2009. 奥巴马当选总统后直到2009年1月20日才就职。可知，奥巴马于2009年1月20日开始就职总统，因此A项正确。
(4) 正确答案为B。根据but America--I have never been more hopeful than I am tonight that we will get there但是美国，我今晚比任何时候都充满希望，我们会达成目标。可知，奥巴马感到充满希望，而且自信，因此B项正确。