5 French Phrases – Find the missing words

What time does boarding start?
Nous embarquons _____ quelle heure ?

We feel like going for a meal
Nous avons _____ d’aller manger

Does he want more cereals?
Il veut _____ des céréales ?

I didn't know anything
Je ne savais _____

I had a big problem
J'ai eu un _____ problème