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
网友回答
A. is
B. are
C. has been
D. have been
解析：句子主语为the time，故用谓语要用单数; 再根据句子前后的时态live和is，可知此处宜用一般现在时，不用现在完成时，故选A。