如图，四边形ABCD内接于⊙O，E为AB延长线上一点，若∠AOC=140°．求∠EBC的度数．

文中共有10处语言错误，每句中最多有两处。每处错误仅涉及一个单词的增加、删除或修改。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:每处错误及其修改均仅限一词；只允许修改10处，多者（从第11处起）不计分。

Dear Mrs.Green,

    I'm Wang Feng, chairman of the Students’ Union of Yucai Middle School, that is close to your university. I'm written to invite you to be a judge at our English speech contest. It will to be held in our school in June 15. It will starts at 2:00 pm and last for about three hours. Ten student will deliver their speeches on the giving topic "Man and Nature". We hope that you will accept our invitation so it is convenient for you. Please call me 44876655 if you have any questions.

    I am looking forward for your reply.

                                                                                                                                  Li Hua

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