单选题 Safety officials have {{U}}earnestly{{/U}} questioned whether the increased use of synthetic materials heightens the risk of fire.
  • A. cautiously
  • B. severely
  • C. accurately
  • D. seriously
【正确答案】 D
【答案解析】[解析] seriously“认真地”与earnestly的意思相吻合，cautiously“小心地；severely”严重地“；accurately”精确地”。