15. After receiving the first prize for the Chinese Bridge in China, Mary went on all the people who had helped in her Chinese study.
A
thanking
B
to thank
C
having thanked
D
to have thanked
句意为：拿到中国桥大赛一等奖之后，玛丽感谢了所有汉语学习过程中给过她帮助的人们。Go on to do，继续做另外一件事，所以选择B。
此题是固定搭配辨析，首先要明确句意，其次判断缺位单词。
固定搭配基本构成。