—What do you think has made Jane so worried?— all the tickets for the stamp show.A. LoseB.

问题补充：

—What do you think has made Jane so worried?

— all the tickets for the stamp show.

A. Lose

B. Lost

C. Losing

D. To lose

答案：

A. Lose

B. Lost

(答案→)C. Losing

D. To lose

解析：考查非谓语动词.句意:你认为是什么让简如此担心?——丢了邮票展的所有的入场券。下文为省略句，动名词做主语表示抽象动作，结合语境可知选C