Answer: it isn't lasting and won't be around for long.
Explanation: it isn't lasting and won't be around for long. -it can't be learned very easily or quickly. -it won't be clear enough to understand. - it doesn't give you time to organize your thoughts.
so, the first sentence informs you that it's raining cats and dogs. when you add the comma after raining, the meaning completely changes. the speaker is telling the cats and dogs that it is raining.
