you didn't really expect the President to () your letter,did you?A.responding toB.responded toC.respond ofD.respond to为什么不能选B呢？

you didn't really expect the President to () your letter,did you?A.responding toB.responded toC.respond ofD.respond to为什么不能选B呢？
you didn't really expect the President to () your letter,did you?
A.responding to
B.responded to
C.respond of
D.respond to
为什么不能选B呢？

you didn't really expect the President to () your letter,did you?A.responding toB.responded toC.respond ofD.respond to为什么不能选B呢？
D
expect sb to do sth 期待某人做某事,固定搭配
to respond to one's letter 回信,固定搭配

D respond to 动词短语，表示对。。。做出回应

D,RESPOND TO 作答、回答
还有 TO 后面一般用动词原形。