How can there be a letter of introduction for Xilin 4 from the wind?

Pick it up, buy it at the store for 1 yuan, and write it yourself in white paper, which is given to calligraphers at random.

White paper can only be written by yourself after reading the letter of introduction. Calligraphers will randomly write scrolls you don't have. If all of them are collected, it seems to be a fixed letter of introduction for you, which may damage your white paper. Pay attention.

so once there is a scroll you haven't read, read it, and then you can write it in white paper. Because you can't write if you find it but haven't read it.