It's not designed for anyone under age eighteen.

　　它不是為18歲以下者設計的。

　　He was employed by them for eighteen years.

　　他為他們工作了18年。

　　Their two faces were hardly more than eighteen inches apart.

　　他倆的臉相隔還不到18英寸。

　　Eighteen boats plied the 1,000 miles of river along a trading route

　　18艘船沿著貿(mào)易航線往返于1,000英里的河面上。

　　He was a kid really, not more than eighteen or nineteen.

　　他實際上還是個孩子，最多不過十八九歲。