第一节：单项选择（共15小题；每小题1分，满分15分）
21. As is known, it was Hu Jintao, ____ president of our nation, who gave ____ lecture at the opening ceremony. （学生命题）
A. the; a B. the; / C. a; the D. /; a
22. My summer job wasn’t ____ fun, but it was ____ real learning experience for me.
A. a; a B. the; / C. /; a D. a; /
23. --- Is there anything wrong with my heart?
--- ______ . Take it easy.
A. Nothing serious B. That’s right C. Don’t mind D. Keep calm
