keyboard operator 复数快,急,现在就要用

keyboard operator和engineer是什么意思? keyboard operator怎么加复数快,求, She is a keyboard operator变为复数 I'm a keyboard operator.汉语怎莫说? keyboard operator 怎么读 用中文 i am a keyboard operator.i operate keyboard.这么说行吗?看新概念看到的keyboard operator keyboard operator 复数快,急,现在就要用 is keyboard operator Tom's father a拼成句子 keyboard .. keyboard 新概念17课`they are keyboard operator为什么用这句```而不是用their are 难道用their operator They usually （listen to the stereo)in the afternoon(针对打扩号的提问）The keyboard operator usually (eats her lunch ) at noon针对打扩号的提问） mechanical keyboard,membrane keyboard keyboard是什么意思 keyboard是什么意思 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? ''operator''是什么意思?