下面文中共有10处语言错误，要求你在错误的地方增加、删除或修改某个单词。

增加：在缺词处加一个漏词符号(∧)，并在该句下面写出该加的词。

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～词；

2.只允许修改10处，多者(从第11处起)不计分。

Dear Gary，

I’m really sorry about my using the mobile phone in your lecture the last week. Please receive my apology for being such rude a student.  But I didn’t use the mobile phone for any reason. I was trying to find a part-time job last week and that day，I got a job offer and they need my further informations immediately. However，I had no other choice but try sending them a text message in class. I promise it will ever happen again. But I do need my phone back to get in touch with others. Will you be kindly enough to give it back to me? Thank you.

Tom

证券公司从事定向资产管理业务，应当自专用证券账户开立之日起（）个交易日内，将专用证券账户报证券交易所备案。

A.15

B.10

C.5

D.3