在正式洗涤前，最好先对沾满油渍的工作服进行预洗。

It's best to ___pre-wash the oil-stained work clothes before the main wash.

这件沾满油渍的工作服需要先进行预洗，然后再进行主洗程序。

These oil-stained overalls need a ___pre-wash before the main cycle.