The funny teacher and the students

If there were only one planet in this universe. What a big planet it would have been. If there were only one country in that planet. what a big country it would have been. If there were only one school in that country. What a famous school it would have been. If there were only one teacher in that school. What an educated teacher he would have been. If there were only one student in that school. What a brilliant student he would have been. If there were only one book in that school. What a big book it would have been containing all knowledge. If there were only one letter in that book. And if it is pronounched as ''ha'' and if the teacher start teaching ''ha''. And if the student start learning''ha''. What a funny teacher and student they would have been. Always laughing ha,ha,ha,