名词 extension:

1. a mutually agreed delay in the date set for the completion of a job or payment of a debt

2. act of expanding in scope; making more widely available

3. the spreading of something (a belief or practice) into new regions

4. an educational opportunity provided by colleges and universities to people who are not enrolled as regular students

5. act of stretching or straightening out a flexed limb

6. a string of characters beginning with a period and followed by one or more letters; the optional second part of a PC computer filename

7. the most direct or specific meaning of a word or expression; the class of objects that an expression refers to

8. the ability to raise the working leg high in the air

9. amount or degree or range to which something extends

10. an additional telephone set that is connected to the same telephone line

11. an addition to the length of something

12. an addition that extends a main building

extensionn.延长；伸展；延期；扩充；观念发展；增强n.电话分机；特别课程n.[计]文件名extensiontypeadj.可抽出的(可伸缩的；伸缩自如)extension rim加宽轮extension fee过期费extension AHP可拓层次分析法extensionlessadj.[哲]无广延性的；无广袤性的extension gap伸缩缝extension die延伸模extension set增设装置,分机extension tap长柄丝锥Extension lag伸展迟缓

1. Your back exercises should include lat pull-downs and back extensions.
   背部的练习应包括前曲和后背伸展。
2. For your biceps and triceps, perform bicep curls, hammer curls, dips, and tricep extensions.
   锻炼二头肌和三头肌，练习二头肌弯曲，锤卷曲，下弯和三头肌伸展。
3. These temporary hive extensions contain frames of empty comb for the bees to fill with honey.
   这些临时的蜂箱扩大了能包含为蜜蜂准备的空巢结构去存蜜。
4. There are telephone extensions in every office.
   每间办公室都有电话分机。