a high command meaning in Chinese

高级司令官

And there is huge demand for english language training among those who have already left school - either because they did not have a chance to learn the language earlier or because they are trying to achieve a higher command of the language
至于那些踏入社会的人，更有迫切掌握英文的需要，也许是因为他们当初没有学习英文的机会，或者此刻他们对英文有更上一层楼的学习动力。