Homewrok for XIIB--deadline 3rd of April 2012

Do you agree or disagree with the following statement? Grades (marks) encourage students to learn. Use specific reasons and examples to support your opinion. 

Please submit your answers by April, the 3rd, 2012, by means of comments (don't forget to sign them, so that I can realise who is the author). Do not write more than 300 words in your answers. For further information on how to structure the answers, you may find inspirations in  argumentative essay writing.
I will appreciate it if you send your answers as comments to this post.
I will not take into consideration the answers submitted later than this deadline.