阻止佢地放聖誕！

Christmas is coming! Student are going to hand in their homework and have a nice holiday. However, their teacher (you) need to prevent them from having a nice holiday. Try to use bug, new homework, weak wifi... to stop the students!!!

(The idea came from our real experience : we have a lot of homework before Christmas. When we want to finish them and have a nice holiday, we face a bug... QAQ)