单选题 This young man has been losing weight by {{U}}working out{{/U}} at the gym at least twice a week.
  • A. making extra money
  • B. doing his utmost
  • C. solving each problem
  • D. taking physical exercise
【正确答案】 D
【答案解析】work out：解答，解决，结果，计算，锻炼；do one's utmost：尽最大努力。