unpredictableadj.不可预知的
unpopularadj.不流行的;不受欢迎的
unprecedentedlyadv.空前地
unprecedented move前所未有的行动
unprecedented risk前所未有的风险
unprecedented sales[经] 空前销售
unprecedented scale史无前例的规模
unprecedented danger空前的危险
unprecedented dilemma前所未有的两难境地
"an unprecedented expansion in population and industry"