They are everywhere and nowhere. They are those who upset bad guys’ bad plans. They are secret agents of the Central Intelligence Agency, simply known _21_ the CIA. The history of the CIA goes back to the WWII, _22_ the Japanese attack on Pearl Harbor made the President Harry Truman set up the CIA. Next, we may wonder what it takes to be an agent for the CIA. People from various different backgrounds _23_ jobs at the agency every year. Some of them are ex-police or soldiers and _24_ have a high level of education. They end up with a _25_ set of skills and get intelligence to their directors without getting found out. In short, the difficulty does not stop many from dreaming of living the life of a James Bond-style secret agent.
【題組】21.
(A) of
(B) to
(C) for
(D) as