They pressed on without letup until they got to the top of the hill.

他们一鼓作气爬上山顶。

《新英汉大辞典》

We should always learn new words and new sentence patterns while keeping practicing without letup.

要源源不断地补充新的词汇、新的句型，并且要坚持不懈地进行练习。

youdao

Even if it a fantasy or an illusion, so long as it shows a ray of hope it still urges you on in pursuit of that little sparkle without letup.

不管是望梅止渴，还是画饼充饥，它都会激励你不停手中的桨，去追逐哪怕一星微小的火光。

youdao

The month's statistics showed a slight letup in prices of residential electric power, which slowed to 0.6% from April's increase of 1.2%.

FORBES: Worst Of Both Worlds

There was no letup by the Hurricanes to start the second half.

NPR: No. 1 Duke Routed By No. 25 Miami 90-63

And when you add in the World Cup, regional tournaments like the Euro and Copa America plus the Olympics and international friendlies, there is no letup.

WSJ: Champions League Soccer: The Sport That Never Takes a Break