prolongation
n. 延伸；延长部分；[经] 延期
例句
The firm refused them a prolongation of the terms of payment.
该公司拒绝了他们延长付款期限的要求。
In this case, prolongation of life should trump reproduction.
既然这样，延长寿命就要重于繁衍后代。
The colour and lustre turned darker with prolongation of heating time.
棕榈油之色泽随煎炸时间延长而加深。
