My contribution to Blog post: http://www.iroon.com/irtn/blog/1309/

یادم رفته اوقات تلخی سر چی بود. از راهنمایی شما سپاسگذار می شوم.

What an interesting question, Ari jan. The boys were burning something in the class fireplace that belonged to one of the girls  The smell becomes intolerable.

You know for all these years I didn't know what actually was burning. So your inquiry put a "kak" into my "tonban" and I said to myself this is 2013 and era of Google search; let's search. Lo and behold, I found this page that explains it all. Simply cllick the question specifically about the class scene in the FAQ section of the following page.

http://www.imdb.com/title/tt0062376/faq

By the way, I found the film script too. Cool!The class scene has been translated almost perfectly. A qualified thank you should go to the Iranian dubbing team in this movie.

http://www.script-o-rama.com/movie_scripts/t/to-sir-with-love-script.html

Enjoy!

Many thanks, Bavafa. Now I get it!

And I quite agree, Iranian dubbing artists were amazing! Many good films in English became masterpieces in Farsi.