I tried to work on, but I was so tired that I could no longer .
A. bear out
B. hold on
C. hold up
D. work out
网友回答
A. bear out
(答案→)B. hold on
C. hold up
D. work out
解析：短语辨析。 bear out 证实；hold on 继续，坚持；hold up 举起；work out解决，计算出。句意：我试图继续，但是我是如此累，以至于我再也不能坚持了，故选B。