保持／跟上 Keep Up & Keep Up With
Story and comic created by CCFamily.
Keep up is a phrasal verb meaning to continue. By adding the preposition "with", it becomes keep up with - another phrasal verb meaning stay on schedule with a person, the work or the homework.
1. Your work is great! Keep it up!
2. I hope I can keep up with the class after the holiday.
3. He reads the news every day to keep up with what's happening in the world.
Reference: Cambridge Dictionaries Online (Learners')