单选题 The old man asked the young sailor if he had ever been ______ in a dense fog.
  • A) by sea
  • B) in the sea
  • C) at sea
  • D) on the sea


【正确答案】 C
【答案解析】by sea: 乘船，经海路 at sea在海上航行；茫然，迷惑：I am quite at sea in regard to his explanation. 他的解释使我如堕五里雾中。