问题补充：
ˉWhat do you think made Tom so upset?
ˉ her new bicycle.
A. Because of
B. Lost
C. As she lost
D. Losing
答案：
A. Because of
B. Lost
C. As she lost
(答案→)D. Losing
解析：本题考查非谓语动词。将答语还原为完整句： her new bicycle made Tom so upset。可发现空白处在句子中充当主语，只能用-ing 形式，答案是losing
