Bonjour,
PRÉSENT PERFECT
has / have + participe passé
Réponse :
a. They have never swum in a river.
b. It is not the first time she has worn such expensive clothes.
c. Have you followed me?
d. He has shown me around the town.
e. It's the first time I have met her.
f. That is the most entertaining show we have ever seen.
Explications :
Attention à la place des adverbes ( ever - never ) : phrases a et f
Forme interrogative : Have / Has + sujet + participe passé ...? (ex: phrase c. )