单选题 At that moment when he was told that the radio station had found his son for him, it was all he could do ______.
  • [A] cry
  • [B] crying
  • [C] to cry
  • [D] cried


【正确答案】 C
【答案解析】固定结构题。it’s all sb can/could do to do sth．这一结构，表示“只能……”的意思，经常用于口语中。故[C]正确。