David studied hard before the examination and it . He made an AA. worked out B. marked

问题补充：

David studied hard before the examination, and it . He made an A.

A. worked out B. marked out C. paid off D. got through

答案：

解析：考查短语。据句意it代指戴维考前努力学习，他获得A，应是努力得到回报，所以选C,pay off意为回报。