pro-,向前，long,长的。引申词义延长。

1. A long drawn out war would likely deepen and prolong the recession.

一场旷日持久的战争很可能会使衰退程度加剧，时间延长。

2. The operation could prolong his life by two or three years.

这次手术可使他多活两三年。

3. He has decided to prolong his visit through the weekend.

他已决定把他的访问延长到过完周末.

4. Doctors commented that some patients deliberately prolong their treatment.

医生说有些病人故意延长治疗时间.

5. The defendant feigns illness to prolong the trial.

为了拖延审判，被告装病。