Envelope or paper bag.

Put the letter written to the child from the 100-day pledge meeting into an envelope, write the child's name and class, and indicate on the envelope that it is for the child to open when attending the 100-day pledge meeting. This method can protect the privacy of the letter and also increase the child's sense of expectation and ritual. You can also put the letter into a beautifully decorated paper bag. You can choose the color and pattern your child likes, so that the child feels surprised and warm.

The College Entrance Examination 100-day swearing-in meeting refers to a large-scale teacher-student meeting held by most high schools when there are only 100 days before the national college entrance examination.