Tom was so busy____the answers from Pingping`s paper that he forgot his name into his.
问题描述：
Tom was so busy____the answers from Pingping`s paper that he forgot his name into his.
A.to copy;to change B.to copy;changing
c.copying;to change D.copying;changing
答
C
be busy (in) doing sth. 其中in可以省略.
forgot to do 是指忘记去做某事
而forgot doing 是指忘记做过的某事.