单选题 While typing, Helen has a habit of stopping {{U}}once in a while{{/U}} to give her long and flowing hair a smooth.
  • A. occasionally
  • B. simultaneously
  • C. eventually
  • D. promptly
【正确答案】 A
【答案解析】[解析] occasionally“偶尔，间或”。simultaneously“同时”；eventually“最终，终于”；promptly“立即；迅速地”。