C42 Solitary Attack!

At the lectern, the teacher was going over the types of exam questions that students commonly got wrong on recent college entrance exams. It was a chemistry class, and the teacher, a man in his forties, seemed older than his years, especially with his noticeably thinning hair. His deep voice resonated as he scratched chalk across the blackboard with a screeching sound.

Chu Jun sat at his desk