1. Eighty years constitute a longer-than-average lifetime.
   八十岁高于平均寿命。
2. ingrained prejudice;the ingrained habits of a lifetime.
   根深蒂固的偏见;一生的根深蒂固的习惯
3. She devoted her lifetime to the study of zoology.
   她以毕生精力从事动物学研究。
4. It's a once in a lifetime chance.
   这是一生难得的机会
5. I am your lifetime companion--the spring mattress.
   我是您的人生伴侣——席梦思床垫。

　1个名词解释