问题补充：
---Have you completing the work given by your boss?
---Not yet, though I have tried to.
A. devoted to
B. succeeded in
C. failed in
D. managed to
答案：
A. devoted to
(答案→)B. succeeded in
C. failed in
D. managed to
解析：考查固定词组。Devote to致力于；succeed in doing sth成功做某事；fail to do sth未能做某事；manage to do sth设法成功做某事；句意：—你完成老板给的任务了吗？—还没有。尽管我已经很努力了。故B正确。
