例句：
1、 I can give you five tens for that fifty if you want.
你愿意的话，我可以给你5张10美元来换那张50美元。
2、She was born in the fifties.
她是五十年代出生的。
3、 He retired in his fifties.
他在五十多岁时退休了。
4、I probably look as if I'm in my fifties rather than my seventies.
我大概看上去像50多岁而不是70多岁。
5、He began performing in the early fifties.
他20世纪50年代初开始从事表演。