Complex sentence: Marge, however, is skeptical of Dr. Nick's real medical qualifications and attempts to decry him for exaggerating Bart's condition, by immediately confronting Hutz for his action and tells him that Dr. Hibbert has been their family physician for years and knows Bart is fine.
Split into simpler sentences: Marge, however, is skeptical of Dr. Nick's real medical qualifications and decries him for exaggerating Bart's condition. She immediately confronts Hutz for his action and tells him that Dr. Hibbert has been their family physician for years and knows Bart is fine.