Use of English PRO

It is believed (0) THAT the Germanic and Celtic cultures in Europe enjoyed a similar type of footwear, though the exact origin of the wooden shoes, or 'clogs', is impossible to say. The oldest surviving clogs date (1) ............ the 13th century and were discovered in Holland. It is of (2) ............ likely that clogs have been fabricated for thousands of years. However, (3) ............ to the fact that they are made in part or completely from wood, older examples (4) ............ the sturdy footwear do not exist. Clogs (5) ............ originally a kind of safety shoe, used in heavy labour, their rigidity giving the wearer a degree of protection from falling hazards in the workplace. Today, the shoes are found worldwide, although there are great variations in the style from region to region because of (6) ............ hand-made nature. Clogs remain today (7) ............ beloved items of fashion wear and as part of traditional costume. They are typically purchased by tourists in countries (8) ............ as Holland, to which they have become, to some degree, synonymous.