expectationn.预料；期望expectation of lifen.平均寿命；平均余年(某一年龄的人尚可期望活的平均年数；可由统计资料显示)expectation-drivenn.期望驱动expectational factor预期因素expectation variance期望值方差expectation operator期望算子expectation criterio期望值准则expectation interest期待利益expectation function期望函数expectation ordering期望序expectation neurosis[医] 期待性神经机能病