单选题 According to the American federal government, residents of Hawaii have the longest life ______:77.2 years.
  • A.rank
  • B.span
  • C.scale
  • D.scope
【正确答案】 B
【答案解析】[解析] B span意为“一段时间”，life span意为“寿命”，故为答案。而A rank意为“排，军衔，地位”，C scale意为“等级，级别”，D scope意为“范围，领域”，都与题意不符，故排除。