专业为英语怎么翻译

『壹』 “专业”用英语怎么说

major;
specialty;
profession;
例句：
1 So are you the professional guitar player?你就是来那个自专业的吉他手吗？
2 What was your major? 你的专业是什么？
3 But he refused those professional actors.
但他拒绝了那些专业演员.