问题
选择题
He has been working hard day and night, which, of course, his tiredness.
A．answers for
B．accounts for
C．applies for
D．stands for
答案
答案：B
考查短语辨析。answers for回答，accounts for做出解释，applies for申请，stands for代表，句意：他一直日日夜夜的工作，当热这就能解释他劳累的原因了。故选B。