单选题 That was so serious a matter that I had no choice but ______ the police.
  • A. called in
  • B. calling in
  • C. call in
  • D. to call m


【正确答案】 D
【答案解析】本题测试but+动词不定式句子结构。这种结构一般有两种模式：have no choice but+带to不定式或have nothing to do but+不带to不定式。