keep on at
像keep going或keep trying都可以！ 另外還有keep on at!! or keep at it!! 也有類似的意思：繼續下去，堅持下去！ keep it up是：繼續奮鬥！！繼續努力！！！
...long gray hair and unclear face. 過去式用had，這句在這裡完結。 She kept [on] looking at him for a couple of minutes when he was lying on the...
...the words that I said 記住我所說的隻字片語 I keep on knocking at your door with my head 我持續以頭叩向你心門 As you'...