In the second line, a colon is added after the capitalized Mr. Wang.
The third line is empty, because I am sick, I hope I can invite the morning and afternoon classes on what date, and I hope the teacher will approve it. Hereby!
The fourth line is empty, salute!
Empty two or three lines, the latter is not empty, (see you)
Write it in the lower right corner, your student: (colon must) Xiaomi.
Write the date, X year, X month, X day and the signature of the last parent in the lower right corner of the next line, otherwise nothing will do.