Answer:
"Twisting" can be a verb or a noun. Words that are commonly used as a verb, but can also be used as a noun are called gerunds. Use determines function. If the sentence is, "She is twisting the towel." twisting is used as a verb. But if the sentence is, "The twisting of the tree bark is intricate." then twisting is used as a noun. You just have to look at the sentence and see what makes sense.