Lefevre Jokes

This comes from Herve' Negre's Dictionnaire des histoires droles, Livre de Poche.
Marcel was a French laborer who was intent on improving himself and his status in life. To that end, he enrolled in night classes and began all too quickly to disgust his fellow workers with his new-found knowledge.
At a lunch break one day, he started again: "I learned something last night that you don't know. What is the name of the person who prevented the Moors from taking over France? You don't know? I'll tell you... it was Charles Martel."
"And what is the name of the man who 'invented' the potato? You won't know - it was Parmentier."
"And what is the name of the scientist who cured smallpox? Let me tell you, it was Pasteur."
And on and on.
Then Jean-Luc broke in, and said, "Tell me who is Alain Lefevre? I'll bet you don't know!"
Marcel thought and thought, but he had never heard of Alain Lefevre. Jean-Luc continued, "You more...