catch up是什么意思啊，

单选28、The best thing about these employees is that they ( ) very fast. A. catch on B. catch up with C. catch D. catch up

catch up 1。 很快拾起 The thief caught up the money and ran away。 小偷一把抓起钱,逃之夭夭。 2。 赶上 They started a few minutes ago, and we must hurry to catch up。 他们几分钟前已出发,我们必须赶紧追上。 3。 缠住 It seemed that she was always caught up in the household。 看来她总是家务缠身。 catch on 1。 抓牢 The girl kept catching on to her mother'...全部

  catch up 1。 很快拾起 The thief caught up the money and ran away。 小偷一把抓起钱,逃之夭夭。 2。 赶上 They started a few minutes ago, and we must hurry to catch up。
   他们几分钟前已出发,我们必须赶紧追上。 3。 缠住 It seemed that she was always caught up in the household。 看来她总是家务缠身。 catch on 1。
   抓牢 The girl kept catching on to her mother's skirt。 小女孩一直紧紧地拉着妈妈的裙子。 2。 理解 I don't quite catch on to what she is saying。
   我不太明白她在说些什么。 3。 流行 It is a nice song and I think it will catch on quickly。 这首歌很好,我想它会很快流行起来。 catch up with 1。
   赶上 Let's hurry and catch up with the group ahead。 我们快点,赶上前面的那一伙人。 2。 对。。。产生预期的坏影响(或恶果) Smoking will catch up with you sooner or later。
   吸烟迟早会使你受害不浅。 说以答案应该是 ch up 跟上。收起