The leader asked me to go to work during the holiday, and I didn't want to go. How can I get rid of it?

If you don't say "I don't want to do these boring things" directly, but say "I didn't solve the problem by preparing for the holiday exam myself", you can express that you are willing to do it, but you really want to use this summer vacation to prepare for the exam. As soon as he heard it, he knew the voice-over. He either asked you for leave or considered making you a frequent visitor! That's probably what it means. Try to be tactful!