- lengthen
 - ['leŋθən]
 - vt. 使延长;加长
vi. 延长;变长 
反义词
           - v. shorten
 
参考例子
           - 1.Open-air exercise undoubtedly have lengthened the old man's life.
 - 户外运动无疑延长了老人的寿命。
 
- 2.To save time is to lengthen life.
 - 节约时间根本那是延长生命。
 
- 3.Mr Duncan is especially interested in proposals to lengthen the school day and year.
 - 邓肯先生对几个延长上学日和上学年的提案尤其感兴趣。
 
英文解释
           - v.
 - 1.make longer
 - 2.become long or longer
 
网络释义
               - lengthen
 - 延长; 拉长 调整长度; 拉长; 加长;
 
- LEN LENGTHEN
 - 直线拉长; 拉长(修改对象的长度和圆弧的包含角);
 
- lengthen symbol
 - 加长符号;
 
- LEN LENGTHEN
 - 长度调整;
 
- lengthen len
 - 拉长; 二维拉长(可以拉长直线或圆弧的圆心角);