sentence: The arrondissement of Haguenau-Wissembourg was formed when the former arrondissements of Haguenau and of Wissembourg were merged on 1 January 2015 to form the new arrondissement.
modified: fix grammar: The arrondissement of Haguenau-Wissembourg were form when the former arrondissements of Haguenau and of Wissembourg are merge on 1 January 2015 to form the new arrondissement.