是work hard at sth.还是work hard on sth.
问题描述：
是work hard at sth.还是work hard on sth.
答
work hard on.固定搭配.致力于..
答
work on sth固定搭配，hard副词修饰work
答
work hard at sth.努力在某物上，加名词。
work hard on doing.固定搭配.致力于，加动名词。
答
work hard at sth.在某方面刻苦、努力
答
work hard at sth.
努力在某事物上,是在某方面刻苦、努力的意思.加名词.
work hard on doing.
固定搭配.致力于,加动名词.