Sentence:  A good formulation will <WSD>keep</WSD> the clothes clean and white after many washings ; whereas , with a poor formulation , the clothes exhibit a build-up of `` tattle-tale grey '' and dirty spots - sometimes with bad results even after the first wash . 
Meaning of the word marked with <WSD> tags:  keep in a certain state, position, or activity; e.g., "keep clean"