I'm a keyboard operater.改错

I'm a keyboard operator.汉语怎莫说? 英语改错：I’m a keyboard operater I'm a keyboard operater.改错 i am a keyboard operator.i operate keyboard.这么说行吗?看新概念看到的keyboard operator I`m a keyboard operaror和I`m an engineer为何要加上a和an,是为我区别男女吗? I（）see a beijing opera tomorrow. And i like Beijing opera ,i like it a ( ) keyboard .. keyboard an和a的用法?SOPHIE:I'm a keyboard operator和ROBERT:I'm an engineer两句话中有a和an两个词.我不清楚为什么分别用这两个词?都用同一个词不行吗? A question about keyboard operatorWhere is colon on the keyboard (yelling and jumping like a child) OH,a soap opera roof party!...(yelling and jumping like a child) OH,a soap opera roof party!I'm going to a soap opera roof party!Oh my God,oh my God!(realizing how she's behaving) And it's out of my system!And it's Beijing opera a fax dose a computer have a keyboard? I like Beijing Opera._______interesting. I like Beijing Opera b___. It’s a keyboard.写问句. She is a keyboard operator变为复数