单选题 The police tried {{U}}in vain{{/U}} to break up the protest crowds in front of the government building.
  • A. unskillfully
  • B. violently
  • C. ineffectively
  • D. eventually
【正确答案】 C
【答案解析】[解析] 本题考查词组。划线词组in vain的意思是“徒劳地，无用地”，与C选项含义相同。