此题要求改正所给短文中的10处错误。请在右边横线上写出改正后的词。包括：多词，缺词和错词。

Dear Editor,

Recently, my classmates have had a heated discussion about that

we should have optional courses in high schools. Some students were

in favor of optional courses. They say interest is best teacher

and our spare time will be colorful and meaningful. Students

can not only enlarge their knowledges but also improve their abilities.

However, others are against the idea, said that optional courses

will take up too much time as well as energy. In addition to, some optional

courses have something to do with the College Entrance Examination. They

are afraid they’ll fall behind their classmates if they will take the

optional courses. I’d like to take one or two of the optional courses, which, I think, will certain benefit me a lot.

Yours truly,

Li Hua