We live day by day but in the great things the time of days and weeks so small that a d

问题补充：

We live day by day, but in the great things, the time of days and weeks so small that a day is unimportant.

A. is

B. are

C. has been

D. have been

答案：

(答案→)A. is

B. are

C. has been

D. have been

解析：考查主谓一致。时间，金钱等做主语，谓语动词用单数，排除BD；本句没有必要使用完成时。故答案为A。