1. He must be eighty now.
   他现在八成有八十岁了。
2. Four times twenty;eighty.
   八十二十的四倍;八十
3. The tree is a bout eighty feet tall.
   这树大约有80英尺高。
4. She's past eighty.
   她已年过八旬。
5. She lived to the age of eighty.
   她活到了80岁。

　3个名词解释