He entered a university ……………………..
A. When he had sixteen years
B. at the age of sixteen
C. When sixteen years were his age
D. at age sixteen years old
đáp án B : at the age of ... (ở độ tuổi bao nhiêu)
- to be on the wrong side of ... = to be over ... : nhiều hơn ... tuổi
- to be on the right side of ... = to be less than ... : it hơn ... tuổi