He appeared behind Su Li this time. Su Li had been battling a math problem for ages without solving it. Just as she was agonizing over it, a voice suddenly came from behind her, "That's wrong."
Su Li whipped her head around and saw Wu Sheng's perpetually pitch-black face.
"You wrote this part wrong..." Wu Sheng continued, looking at Su Li's problem.
Su Li clutched her chest. "You scared me to death!"
'He's like a ghost!'
"I've been sitting here for half an hour. It's your fault for not noticing me again."
Wu Sheng sounded aggrieved. He shook his head and came to a conclusion once again, "You really are a bookworm."
Su Li: "..."
She backed away a little. "You really sat there for another half an hour?"
'Why didn't I even hear him breathing!'
"No... more like fifteen minutes. I was going to wait for you to finish this problem, but after fifteen minutes, you still couldn't solve it, so I couldn't help myself."
