短语词组短語back bone lining up machine 書脊粘紗佈機bone up detail 抓緊溫習bone up World 努力研讀bone up on 努力研讀;專心致志於;專門鑽研;鑽研to bone up on 鑽研bone up for 突擊鑽研bone up to 學習bone up on a subject 專攻一門學問Bone up on a problem 突擊鑽研一個問題 返回 bone up