Add spaces: PesticidesconstituteaseriousproblemforthegroundwaterresourceandthewaterworksinDenmark.

Answer: Pesticides constitute a serious problem for the groundwater resource and the water works in Denmark.

Add spaces: WesternBelarushasanimportantPolishminority,especiallyintheBrestandGrodnoregions.

Answer: Western Belarus has an important Polish minority, especially in the Brest and Grodno regions.

Add spaces: Thefine-meshdirtfiltermadeofstainlesssteelguaranteeseasycleaning.

Answer:
The fine-mesh dirt filter made of stainless steel guarantees easy cleaning.