Catch up 趕上;與別人看齊 I'd love to go with you but I've got some catching up to do. 我也想跟你一起去,但我還得先趕進度。
Behind 在後面;落後;忘掉過去。 Look behind you! Something is coming! 看你身後!有東西過來了! I'm behind in my work. 我積壓了很多工作。 The accident is behind you now, so try to forget it. 那場事故已經過去了,忘了它吧