he was a rising film star in China but now few young people know him.A. At a timeB. All t

问题补充：

he was a rising film star in China, but now few young people know him.

A. At a time

B. All the time

C. At one time

D. At times

答案：

A. At a time

B. All the time

(答案→)C. At one time

D. At times

解析：

这题考查词组：At a time一次，.All the time一直，.At one time曾经，At times有时，

根据句意：他曾经是中国的崛起的电影明星，可是现在很少年轻人认识他，选C。