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。