基因主要位于细胞核内的____ 上，____ 是____ 存在的，所以基因也是成对存在的。

增加：在缺词处加一个漏字符号（∧），并在其下面写出该加的词。

删除：把多余的词用斜线（\）划掉。

修改：在错的词下划一横线，并在该词下面写出修改后的词。

注意：1）每处错误及其修改均仅限一词；

2）只允许修改10处，多者（从第11处起）不计分。

Dear Mr. Smith,

    I'm writing to invite you to the Traditional Chinese Cultural Fair be held by our school at the Art Center this Friday afternoon, at 2p.m .to 5p.m.

    Since a event aims to help more people learn about the traditional Chinese culture, the staff, all the students and their parents as well as anyone interested in it is welcome. At the fair, relating books, pictures, videos and objects will be exhibited, through that visitors will not only understand traditional Chinese culture better but definitely feel about the unique beauty of it.

    If you were interested, please come and enjoy them. And I'd be glad to offer any helps. Looking forward to your early reply.

Yours,

Li Hua