Question

Everyone had a form in his hand, but no one knew which office____．

1. A.
   to send it to
2. B.
   to sent it
3. C.
   to be sent to
4. D.
   to have it sent

Answer 1

A
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。