I was twenty years old and ready for anything.

　　我當時二十歲，什么都愿意去做。

　　Twenty guests are enough, I would have thought.

　　我覺得二十位客人就夠了。

　　There were twenty or so people there.

　　那兒有差不多二十個人。

　　Pick a number from one to twenty.

　　從一至二十中挑選一個數(shù)。

　　He finally won his freedom after twenty years in jail.

　　他蹲了二十年監(jiān)獄以后終于獲得了自由。