Ten years a long time in one’s life.A. has beenB. areC. isD. have been

问题补充：

Ten years a long time in one’s life.

A. has been

B. are

C. is

D. have been

答案：

A. has been

B. are

(答案→)C. is

D. have been

解析：考查主谓一致。时间，金钱，距离等做主语时，谓语动词应用单数形式，句意：在人生当中十年是一段很长的时间。根据语境应用一般现在时，故选C。