shorten: implies a reduction in length OR duration: ~ the speech to Fit the allotted time.

curtail: adds an implication of cutting that in some way deprives of completeness or adequacy: ceremonies ~ because of the rain.

abbreviate: implies a making shorter usually by omitting or cutting off some part: hostile questioning that ~ the interview.


abridge: implies a reduction in compass or scope with retention of essential elements and relative completeness of the result: the ~ version of the novel.


retrench: suggests a reduction in extent of something felt to be excessive: falling prices forced the company to ~.


shorten: 泛指长度或时间减少，curtail: 剪掉使不再完整充分，abbreviate省略: 忽略或切除一部分以变短，abridge: 缩小范围但保持精华完整，retrench: 减少过量的东西。



记忆方法: 1）SCAAR: 首字母是一个伤疤A SCAR==>努力缩减。
   

        2）缩减的意思是减少范围mean to reduce in extent.