Everyone had a form in his hand, but no one knew which office ．
A. to send it to
B. to sent it
C. to be sent to
D. to have it sent
网友回答
(答案→)A. to send it to
B. to sent it
C. to be sent to
D. to have it sent
解析：考查定语从句。句意：没有人知道把它寄到哪个办公室。句子可还原：不是定语从句时应该是to send it to that office room，要换成定语从句office room 作为先行词提前，并把that 换成 which修饰office。