— What do you think made Mary so upset？— her new bicycleA. As she lostB. She lostC. Los

问题补充：

— What do you think made Mary so upset？— her new bicycle．

A. As she lost

B. She lost

C. Losing

D. Because of losing

答案：

A. As she lost

B. She lost

(答案→)C. Losing

D. Because of losing

解析：考查动名词作主语。此句省略了谓语和宾语，补充完整是：— What do you think made Mary so upset？— her new bicycle made her so upset.缺少主语，所以用Losing。选C。