I don’t when I fail something.
A. lose my heart; doing
B. lose heart; to do
C. discouraged; in doing
D. be discourage; to do
网友回答
A. lose my heart; doing
(答案→)B. lose heart; to do
C. discouraged; in doing
D. be discourage; to do
解析：考查短语： lose heart 失去信心， fail to do 失败做某事，句意：当我失败做某件事情的时候我不会失去信心的。故选B。