have good command of中间有a吗

有
have a good command of释义 熟练掌握
1. An English teacher should have a good command of the English language and provide necessary background knowledge when giving English lectures. 作为一名英语教师，应对英语语言比较精通，而且在给学生授课时需提供必要的英语背景知识以便于学生更好地掌握所学知识内容。