"Knock, knock, knock…"
The door to the office was knocked, and the teachers busy labeling papers were too lazy to get up, immediately saying,
"Come in, the door's not locked."
However, no one entered.
Only the continued "knock, knock, knock"…
Playing pranks by knocking on doors is a very common form of mischief, but the problem was, daring to play such a prank on a teacher's office door was truly unparalleled.
"Knock, knock, knock…"
Perhaps genuinely annoyed by the disturbance, finally, a teacher stood up, angrily walked towards the door, but didn't open it immediately, just stood behind it, silently waiting.
"Knock…"
As soon as the knocking stopped, he abruptly opened the door, but to his surprise, there seemed to be nothing outside.
