How do you create multiple fill-in answers in one box ?

I'm trying to create a quizz in French (since I'm french) about World heritage sites in France. Since their name can be quite complicated, I decided to make it a fill-in quizz to make it easier. My problem is that for many (most) of those sites, I'd want the players to fill in multiple words.

Here's an example : "Les Causses et les Cévennes, paysage culturel de l'agro-pastoralisme méditerranéen". For this UNESCO site, I want both "Causses" and "Cévennes" to be answers. So initially, a player would see "Les _____ et les _______, paysage culturel de l'agro-pastoralisme méditerranéen" ; if a player only fills in Causses, for instance, I want the quizz to display "Les Causses et les _______, paysage culturel de l'agro-pastoralisme méditerranéen", in one block, until they find the Cévennes.

I know to make fill in answers, you use {}, but if I simply put "Les {Causses} et les {Cévennes}, paysage culturel de l'agro-pastoralisme méditerranéen", the quiz wants the player to fill "causses cévennes" both at the same time, so it doesn't work as I want it to. I've also tried creating different answer rows for Causses and Cévennes, but I can't find a way to edit it manually in the design grid either.

Can anyone help me with that?