B1
not interesting
Dictionary examples:
The teacher's lecture was so uninteresting, students started counting ceiling tiles for fun. (0.0)
The movie was so uninteresting, I started reading the nutrition facts on my popcorn. (0.0)
The book was so uninteresting, I used it as a pillow instead. (0.0)
His later work is uninteresting in comparison with his first novel. (35.5)