Keeping something up your sleeve means that you are trying to fool someone.

后者的意思是你试图愚弄某人。

To keep something up means to continue to do something.

To keep something up 意思是继续做某事。

To " keep something up" or to " keep up something" here means to continue to do something, especially something that is difficult or challenging.

“keep something up” 或“keep up something” 在这里的意思是继续做某事， 尤指困难或有挑战性的事情。