She has been working hard day and night which of course her pale face.A. accounts forB.

问题补充：

She has been working hard day and night, which of course, her pale face.

A. accounts for

B. stands for

C. goes for

D. results from

答案：

(答案→)A. accounts for

B. stands for

C. goes for

D. results from

解析：句意:她日日夜夜的工作这使她的脸色苍白。account for说明……的原因；stand for代表，支持；go for主张，拥护；result from起因于。根据句意故选A。