---What’s made Ruth so upset?
--- three tickets to the folk music concert.
A. Lost
B. Losing
C. Because of losing
D. Since she lost
网友回答
A. Lost
(答案→)B. Losing
C. Because of losing
D. Since she lost
解析：根据问句：什么使如斯如此伤心呢？可推断出示对主语进行提问，从四个选项中可以看出B. Losing 可做主语，其余三项不能，所以选B。